Luminous Landscape Forum

Raw & Post Processing, Printing => Printing: Printers, Papers and Inks => Topic started by: shadowblade on July 10, 2013, 03:20:00 AM

Title: Inkjet printing on uncoated paper - anyone tried it?
Post by: shadowblade on July 10, 2013, 03:20:00 AM
Has anyone here done much printing on uncoated paper? Fine art paper, that is, not throwaway prints on copy paper.

How did they turn out, in terms of sharpness, Dmax and colour saturation, using optimised custom profiles? What printer, ink and paper combination did you use? Did you use sized or unsized papers

Some of the ultra-heavy watercolour papers - Arches Watercolour Hot Press in the 640gsm and 850gsm weights, for example - as well as ultra-heavy Japanese washi papers, look like they'd make beautiful and long-lasting substrates. Indian khadi and Nepalese/Bhutanese handmade papers (which are also acid-free, lignin-free, sized and buffered), too, would add a nice touch to photos taken in those areas. Of course, none of these papers have inkjet coatings, and the very durability of receptive coatings (not to mention Inkaid) is questionable anyway.

The literature seems to suggest that a high (15%) concentration of calcium chloride in the external sizing tub makes for a higher DMax and reduced dot-gain with inkjet pigment inks, as do styrene-acrylic emulsion sizers, while external sizing with starch has a deleterious effect on both DMax and dot gain. The concentration or type of internal sizing does not appear to have any effect. Does anyone have experience with the Arches Watercolour papers, or other similar papers which are sized with gelatin? I couldn't find much information about those.

A hydrophobic, oleophilic surface would also serve to reduce ink absorption while minimising dot gain. Also, heating the ink and paper would increase the possible ink load while speeding up the drying time (and thus reducing dot gain) - this is obviously possible with solvent printers, or solvent printers converted to use aqueous inks, but no HP, Canon or Epson printer has a paper or ink pre-warmer. Maybe an 'oven chamber' for the printer, to keep it at 50 degrees and minimal relative humidity, could work?

Is it possible, or advisable, to size, or re-size, papers at home prior to printing, to optimise the paper for inkjet printing as much as is possible, without adding an inkjet coating? Or would it be better to have papers made and sized to chemical specification by a small, niche paper mill willing to work with individual, low-volume clients, in the knowledge that I might have to go through the whole process again should they go out of business?

Any other intelligent thoughts or ideas that I'm missing here?
Title: Re: Inkjet printing on uncoated paper - anyone tried it?
Post by: Pete Berry on July 10, 2013, 09:12:38 AM
Seems like all you would need to do is to print on the uncoated back of some of these art papers, as I'm sure we've all done - a mess, of course with the normal ink load, which would not be encouraging to me for further experimentation!

Pete
Title: Re: Inkjet printing on uncoated paper - anyone tried it?
Post by: hugowolf on July 10, 2013, 10:01:14 AM
Zone8, on the DPReview printers forum, has printed on uncoated fine art papers for many years. I think mostly black and white, but maybe also color. You could try asking on that forum.
http://www.dpreview.com/members/2328968436

I have tried several uncoated papers. Some seem to work well, others not. Arches Aquarelle is one that works, but the few Bristols I have tried do not. I would imagine that Rives BFK (called BFK Rives when sold as a coated inkjet paper) would do well too - it is a traditional fine art printing paper (monotype, lino print, woodcut, mezzotype, engraving, etching, etc.) It is soft sized. Arches Aquarelle is fully sized.

Papers designed for pastel, graphite, charcoal, crayon, etc, would proibably not do well. Papers designed for pastel, chalk, and charcoal, often have a destinctive regular honeycomb texture.

Brian A
Title: Re: Inkjet printing on uncoated paper - anyone tried it?
Post by: Rob Reiter on July 10, 2013, 12:47:25 PM
I've done a lot of printing on uncoated papers, particularly Japanese and other Asian art papers. To some degree, it will depend on the ink, but with my Canon iPF 8400 I've had good success. In general, you'll find color saturation is lower and max blacks aren't as dense, but picking the right images will produce quite attractive prints when you factor in the papers themselves. I like the look of monochromatic images, either straight grayscale or various sepia or warm tone looks best. Sometimes I'm surprised at how well full color can look.

Hiromi Paper in Santa Monica is a good source of Japanese papers, some even coated for inkjet printing.

I'ved had good luck with Arches Cold Press as well as some of my old "Iris" sized sheets of Somerset Velvet from the olden days (1990s.)

Experiment with ink loading to balance out dot gain and max density. Try some of the thin, translucent kozo (mulberry fiber) papers, especially with black and white images.

And to truly appreciate the look of some of these papers with their nice textures and mould-made edge deckling, float them in the frame with no over matting.
Title: Re: Inkjet printing on uncoated paper - anyone tried it?
Post by: TylerB on July 10, 2013, 05:47:37 PM
I've also done a lot of printing on uncoated fine art papers, both Epson OEM ink and Cone B&W inks, and still do. Arches, Somerset, Japanese papers, etc etc. I use a RIP which let's me address all the issues one imagines on unconventional substrates, but I can tell you it works and beautiful prints are possible. You give up gamut and dmax for other subtle qualities some artists might value.
Without a RIP, your path would be to make several tests on these papers trying all the media setting options, find one that doesn't mottle or bleed, but is hopefully not too weak, then of course a custom profile has to be made for that setting and that paper.
Here is an example of a project done on Arches-
http://tylerboley.com/liz/elizabeth-gallery/

Tyler
Title: Re: Inkjet printing on uncoated paper - anyone tried it?
Post by: shadowblade on July 10, 2013, 07:19:13 PM
Seems like all you would need to do is to print on the uncoated back of some of these art papers, as I'm sure we've all done - a mess, of course with the normal ink load, which would not be encouraging to me for further experimentation!

Pete

I don't own a printer myself - I just hire their services, and try all sorts of unusual things with them!
Title: Re: Inkjet printing on uncoated paper - anyone tried it?
Post by: shadowblade on July 10, 2013, 07:45:28 PM
Seems like all you would need to do is to print on the uncoated back of some of these art papers, as I'm sure we've all done - a mess, of course with the normal ink load, which would not be encouraging to me for further experimentation!

Pete

This may not be the best option - as far as I know, a lot of inkjet papers are unsized, relying on the inkjet receptive coating to control absorption, which is quite different from actual papers used in watercolours or traditional printing.
Title: Re: Inkjet printing on uncoated paper - anyone tried it?
Post by: shadowblade on July 10, 2013, 08:46:05 PM
I've done a lot of printing on uncoated papers, particularly Japanese and other Asian art papers. To some degree, it will depend on the ink, but with my Canon iPF 8400 I've had good success. In general, you'll find color saturation is lower and max blacks aren't as dense, but picking the right images will produce quite attractive prints when you factor in the papers themselves. I like the look of monochromatic images, either straight grayscale or various sepia or warm tone looks best. Sometimes I'm surprised at how well full color can look.

I thought the main reason that colour saturation was lower was because of ink bleed/dot gain causing reduced contrast (if you use the regular amount of ink) or because of lower pigment load (if you use less ink to combat dot gain).

If you could increase the (surface) ink load while minimising dot gain (e.g. by heating the paper/ink, or the room in which the printer is located, as well as reducing the relative humidity, such as by using a reverse-cycle air conditioner in combination with some strong heaters or a printer with an inbuilt heater, by changing the solvent in which the pigments are suspended to a faster-evaporating one, by increasing the pigment load per unit of ink, or by using an inkjet-friendly formulation for the external sizing of the paper) would you also increase the Dmax and saturation? I'd also imagine that printing on a smoother surface, e.g. Hot Press, would give you better DMax than rougher surfaces.

Quote
Hiromi Paper in Santa Monica is a good source of Japanese papers, some even coated for inkjet printing.

I know. I've seen some of their papers, and they'd make fantastic substrates. Also, the (uncoated) Japanese papers have an even longer record of durability for fine art and calligraphy than European watercolour papers (paper having existed in the Far East and India for centuries longer than in the West).

They also make custom papers - if all goes well, I wouldn't mind having moulds made for extra-thick (I'm talking 3-4mm thick here), 100% Kozo, or 50% Kozo-50% cotton papers in a number of sizes that I commonly print, fully sized and buffered, and with a strong calcium chloride bath as part of the tub sizing process.

Quote
I'ved had good luck with Arches Cold Press as well as some of my old "Iris" sized sheets of Somerset Velvet from the olden days (1990s.)

How did they go in the DMax and colour saturation department, compared to standard matte inkjet paper?

Quote
Experiment with ink loading to balance out dot gain and max density. Try some of the thin, translucent kozo (mulberry fiber) papers, especially with black and white images.

Do they hold up well? They look rather fragile to me, and seem like they'd be very prone to wrinkling while drying from high ink loads, or due to humidity. But appearances can be deceptive.

Quote
And to truly appreciate the look of some of these papers with their nice textures and mould-made edge deckling, float them in the frame with no over matting.

How do you float them archivally?
Title: Re: Inkjet printing on uncoated paper - anyone tried it?
Post by: Rob Reiter on July 11, 2013, 04:39:39 PM
"reverse-cycle-air conditioner..." Not for me. I print on paper for what it offers, rather than trying to change it into something else. You might get slightly better Dmax on a hot press paper, but the above still applies.

I'd say the uncoated Somerset Velvet was similar to the heavier Japanese papers in its saturation and Dmax.

The thinner kozo papers are particularly prone to cockling if the ink load is too great. Won't work for everything, but when they do...!

Awagami is now importing some nice coated papers through Freestyle Photographic (http://www.freestylephoto.biz) in L.A. One of my favorites is the Bizan, a hand-made paper with mould made deckles on all four sides. Gorgeous...at $50 a sheet for A2 (roughly 17x23.)  :(

I thought the main reason that colour saturation was lower was because of ink bleed/dot gain causing reduced contrast (if you use the regular amount of ink) or because of lower pigment load (if you use less ink to combat dot gain).

If you could increase the (surface) ink load while minimising dot gain (e.g. by heating the paper/ink, or the room in which the printer is located, as well as reducing the relative humidity, such as by using a reverse-cycle air conditioner in combination with some strong heaters or a printer with an inbuilt heater, by changing the solvent in which the pigments are suspended to a faster-evaporating one, by increasing the pigment load per unit of ink, or by using an inkjet-friendly formulation for the external sizing of the paper) would you also increase the Dmax and saturation? I'd also imagine that printing on a smoother surface, e.g. Hot Press, would give you better DMax than rougher surfaces.

I know. I've seen some of their papers, and they'd make fantastic substrates. Also, the (uncoated) Japanese papers have an even longer record of durability for fine art and calligraphy than European watercolour papers (paper having existed in the Far East and India for centuries longer than in the West).

They also make custom papers - if all goes well, I wouldn't mind having moulds made for extra-thick (I'm talking 3-4mm thick here), 100% Kozo, or 50% Kozo-50% cotton papers in a number of sizes that I commonly print, fully sized and buffered, and with a strong calcium chloride bath as part of the tub sizing process.

How did they go in the DMax and colour saturation department, compared to standard matte inkjet paper?

Do they hold up well? They look rather fragile to me, and seem like they'd be very prone to wrinkling while drying from high ink loads, or due to humidity. But appearances can be deceptive.

How do you float them archivally?
Title: Re: Inkjet printing on uncoated paper - anyone tried it?
Post by: Rob Reiter on July 11, 2013, 04:41:50 PM
Use an archival mounting tape on the back of the print. There are standard framer's techniques for this. I even have a print on translucent kozo paper done this way using a transparent framers tape and the tape is not visible (framing done by a pro, not me!)


How do you float them archivally?
Title: Re: Inkjet printing on uncoated paper - anyone tried it?
Post by: shadowblade on July 11, 2013, 06:35:59 PM
"reverse-cycle-air conditioner..." Not for me. I print on paper for what it offers, rather than trying to change it into something else. You might get slightly better Dmax on a hot press paper, but the above still applies.

One could argue that the whole concept of inkjet coatings was developed in order to make inkjet prints look like chromagenic prints without having to modify the print process!

Have you, or anyone else you know, done any actual DMax measurements or gamut plotting for uncoated papers?

Quote
I'd say the uncoated Somerset Velvet was similar to the heavier Japanese papers in its saturation and Dmax.

Thanks - very useful to know.

Quote
The thinner kozo papers are particularly prone to cockling if the ink load is too great. Won't work for everything, but when they do...!

I'd have imagined they'd be good for black-and-white printing, a bit like traditional calligraphy or ink painting/drawing. Can you get rid of the cockling by sizing the paper, or by pressing it afterwards?

Quote
Awagami is now importing some nice coated papers through Freestyle Photographic (http://www.freestylephoto.biz) in L.A. One of my favorites is the Bizan, a hand-made paper with mould made deckles on all four sides. Gorgeous...at $50 a sheet for A2 (roughly 17x23.)  :(

I've seen the Bizan too - it looks and feels fantastic.

One of the attractions of printing on uncoated paper, though, quite apart from the range of papers available, is the proven longevity of the medium - there's no tennis-court-sized surface area to increase oxidation of pigment particles, and there's no coating which can crack or peel if the binder becomes brittle or otherwise fails. If one could develop an inkjet printing or paper sizing (or combined) process whereby you could print on uncoated paper, while getting a similar Dmax and saturation to current processes on coated paper, you'd be opening up a whole world of printing possibilities, both in artistic and archival terms.

Any idea if it's possible to re-size a paper that's already been externally sized, to change the sizing chemistry to a more inkjet-friendly one? Or would it have to be a custom order? Any suggestions for sizing your own paper at home, while minimising curling and wrinkling? I'd imagine it would be easier with super-heavy papers than with thinner ones.
Title: Re: Inkjet printing on uncoated paper - anyone tried it?
Post by: Rob Reiter on July 12, 2013, 12:59:09 PM
There is also this company, inkAID (http://www.inkaid1.com), which sells coatings you can apply. I've only experimented a little with them and can't say anything conclusively at this time.

I haven't tried any forced flattening of cockled paper. But when I've coated both sides of a sheet of thicker paper, it does help reduce curl that can cause printer head strikes.
Title: Re: Inkjet printing on uncoated paper - anyone tried it?
Post by: shadowblade on July 12, 2013, 07:28:42 PM
There is also this company, inkAID (http://www.inkaid1.com), which sells coatings you can apply. I've only experimented a little with them and can't say anything conclusively at this time.

I haven't tried any forced flattening of cockled paper. But when I've coated both sides of a sheet of thicker paper, it does help reduce curl that can cause printer head strikes.

I've seen and used Inkaid before - basically, it lets you turn anything that will fit into the printer, including leather, denim and wooden panels, into an inkjet surface. But I certainly can't vouch for its archival value - if I just wanted a paper with an inkjet coating, there are plenty of those out there already!
Title: Re: Inkjet printing on uncoated paper - anyone tried it?
Post by: shadowblade on July 17, 2013, 06:29:55 AM
I've also done a lot of printing on uncoated fine art papers, both Epson OEM ink and Cone B&W inks, and still do. Arches, Somerset, Japanese papers, etc etc. I use a RIP which let's me address all the issues one imagines on unconventional substrates, but I can tell you it works and beautiful prints are possible. You give up gamut and dmax for other subtle qualities some artists might value.
Without a RIP, your path would be to make several tests on these papers trying all the media setting options, find one that doesn't mottle or bleed, but is hopefully not too weak, then of course a custom profile has to be made for that setting and that paper.
Here is an example of a project done on Arches-
http://tylerboley.com/liz/elizabeth-gallery/

Tyler

Zone8, on the DPReview printers forum, has printed on uncoated fine art papers for many years. I think mostly black and white, but maybe also color. You could try asking on that forum.
http://www.dpreview.com/members/2328968436

I have tried several uncoated papers. Some seem to work well, others not. Arches Aquarelle is one that works, but the few Bristols I have tried do not. I would imagine that Rives BFK (called BFK Rives when sold as a coated inkjet paper) would do well too - it is a traditional fine art printing paper (monotype, lino print, woodcut, mezzotype, engraving, etching, etc.) It is soft sized. Arches Aquarelle is fully sized.

Papers designed for pastel, graphite, charcoal, crayon, etc, would proibably not do well. Papers designed for pastel, chalk, and charcoal, often have a destinctive regular honeycomb texture.

Brian A


I've done a lot of printing on uncoated papers, particularly Japanese and other Asian art papers. To some degree, it will depend on the ink, but with my Canon iPF 8400 I've had good success. In general, you'll find color saturation is lower and max blacks aren't as dense, but picking the right images will produce quite attractive prints when you factor in the papers themselves. I like the look of monochromatic images, either straight grayscale or various sepia or warm tone looks best. Sometimes I'm surprised at how well full color can look.

Hiromi Paper in Santa Monica is a good source of Japanese papers, some even coated for inkjet printing.

I'ved had good luck with Arches Cold Press as well as some of my old "Iris" sized sheets of Somerset Velvet from the olden days (1990s.)

Experiment with ink loading to balance out dot gain and max density. Try some of the thin, translucent kozo (mulberry fiber) papers, especially with black and white images.

And to truly appreciate the look of some of these papers with their nice textures and mould-made edge deckling, float them in the frame with no over matting.

By the way, when using custom RIPs for uncoated paper (always better than just a custom ICC profile), what RIP software did you use? I'm assuming you had to do a lot of adjustments to compensate for increased dot gain and different absorbency characteristics of uncoated paper. It seems that, with a good RIP, Arches Watercolour Hot Press can outdo the Dmax and gamut of coated matte papers - how did you come up with the RIP, to saturate the paper with sufficient ink for good saturation and Dmax (sized paper makes this easier, though) without the paper warping and wrinkling due to the ink load? Also, how did you rebalance all the inks for accurate colour reproduction, particularly on printers capable of multiple dot volumes (not all RIP software can adjust this)? I'm guessing you had to do this whether printing using OEM inks with a custom RIP, or using various third-party inks for a custom inkset.

DPReview forum is a snakepit of ignorance and politics I'd hesitate to venture into, for almost anything...
Title: Re: Inkjet printing on uncoated paper - anyone tried it?
Post by: TylerB on July 17, 2013, 01:37:14 PM
By the way, when using custom RIPs for uncoated paper (always better than just a custom ICC profile), what RIP software did you use? I'm assuming you had to do a lot of adjustments to compensate for increased dot gain and different absorbency characteristics of uncoated paper. It seems that, with a good RIP, Arches Watercolour Hot Press can outdo the Dmax and gamut of coated matte papers - how did you come up with the RIP, to saturate the paper with sufficient ink for good saturation and Dmax (sized paper makes this easier, though) without the paper warping and wrinkling due to the ink load? Also, how did you rebalance all the inks for accurate colour reproduction, particularly on printers capable of multiple dot volumes (not all RIP software can adjust this)? I'm guessing you had to do this whether printing using OEM inks with a custom RIP, or using various third-party inks for a custom inkset.

DPReview forum is a snakepit of ignorance and politics I'd hesitate to venture into, for almost anything...

I guess you're asking me amongst others...
I use Ergosoft PosterPrint. Dot gain and absorbancy are dealt with the normal ways.. with light ink limiting, individual channel linearization and limiting. Total ink limiting, K generation, O & G generation, these things also effect those issues and are done in the profiling after the other issues are controlled. Rebalance? Again, that would be taken care of in profiling, over a well linearized and limited paper setup. Dot settings are all totally controllable and also play a role to help minimize mottle and bleed on those kids of papers. No, densities and gamut on Arches, no matter how carefully set up, will not exceed the good coated fine art papers, nor will resolution. For monochrome with Cone inks, all the above applies, but since it's a 2d space, linearization to a chosen output standard is the end of the process, not profiling. But again, all the dot stuff and light ink and max density limiting has to be carefully done to maximize on specialty papers. Getting into more detail about all of this is more like a PosterPrint tutorial and very very few will be interested...
Tyler
Title: Re: Inkjet printing on uncoated paper - anyone tried it?
Post by: shadowblade on July 17, 2013, 08:53:48 PM
Thanks.

I guess you're asking me amongst others...
I use Ergosoft PosterPrint.

Does this differ much from StudioPrint (also by Ergosoft)? How many individual colours (not including light/diluted versions) does it support? Does it support variable drop size?

Quote
Dot gain and absorbancy are dealt with the normal ways.. with light ink limiting, individual channel linearization and limiting.

Apart from pure carbon inks (which are completely stable regardless of dilution), I'd prefer to avoid light ink wherever possible, due to the reduced lightfastness of diluted inks. Better to use smaller dots of full-concentration inks, rather than diluted inks. If only the standard Epson heads went down to 1.5 picolitres, using a combination of 3pL and 1.5pL dots for the highest print quality... How much would removing all the light inks cost me, gamut-wise? Could this be made up for by introducing more dilutions of black ink (up to 7, as with Cone inks) or by using more inks of nonstandard colours? Just as importantly, would your RIP program be able to handle an inkset which included red, green, orange, brown and other ink colours, in addition to the standard CMYK?



Quote
Total ink limiting, K generation, O & G generation, these things also effect those issues and are done in the profiling after the other issues are controlled.

Shouldn't K generation, as well as orange/green and other colours, be done in the RIP, controlling individual inks, rather than in the ICC printer profile?

Ideally, for Lab values equalling those produced by the pure carbon pigments on paper, you'd want to set it so that the only inks used to generate those colours were the carbon pigments, with no coloured inks at all. You couldn't do this in the ICC profile. Same with black-and-white RIPs - you'd set it so that only the pure carbon inks were used, or with small amounts of coloured inks for toning.

Linearising a specific ink colour is easy enough - it's just a matter of measuring density and Lab values along a gradient of that particular ink colour. The hard part is getting all the various coloured inks to work together - particularly if there are nonstandard inks like red, green or brown - to produce whatever RGB values are forwarded to the RIP via the printer profile. How good is Posterprint for this sort of thing?

Quote
Rebalance? Again, that would be taken care of in profiling, over a well linearized and limited paper setup. Dot settings are all totally controllable and also play a role to help minimize mottle and bleed on those kids of papers.

In other words, using the RIP , and an ICC profile to convert the file's Adobe RGB colour space into the equivalent RGB values for the printer's colour space, which the RIP can then use to determine the exact mixture of inks needed to replicate that particular colour?

Quote
No, densities and gamut on Arches, no matter how carefully set up, will not exceed the good coated fine art papers, nor will resolution.

I once saw a recorded Dmax of 1.7 on Arches Hot Press. This was with preheated inks and paper on a solvent printer, using a single-pass technique (multiple passes could achieve a deeper Dmax, but would add further problems with registration and profiling).

I wonder if replacing the solution in which the pigment particles are suspended with an alcohol-based, rather than water-based solution (still aqueous, since ethanol is water soluble) would improve things, since alcohol's faster evaporation would reduce dot gain and increase possible ink load. Keeping the pigment from settling would be a challenge, though.

Quote
Getting into more detail about all of this is more like a PosterPrint tutorial and very very few will be interested...
Tyler

I guess that's why it's an individual thread on a very specialised subforum on a website that is itself specialised!
Title: Re: Inkjet printing on uncoated paper - anyone tried it?
Post by: hugowolf on July 17, 2013, 09:10:52 PM
I once saw a recorded Dmax of 1.7 on Arches Hot Press.

I've seen 1.79 on Epson Hot Press Natural with an Epson 3800.

Brian A
Title: Re: Inkjet printing on uncoated paper - anyone tried it?
Post by: shadowblade on July 17, 2013, 09:15:05 PM
I've seen 1.79 on Epson Hot Press Natural with an Epson 3800.

Brian A

Not at all surprised.

I'm not saying that Arches watercolour beats *every* coated matte paper out there, when printed in the right way.

I'm merely saying that it can beat *some* coated papers (some max out at 1.45-1.5) and, Dmax- and saturation-wise, doesn't necessarily have to be inferior to coated papers.

Obviously, none of these can hold a candle to lustre and gloss papers, but, as with coated matte papers, you can also wax or spray uncoated papers to increase their Dmax and saturation.
Title: Re: Inkjet printing on uncoated paper - anyone tried it?
Post by: Ernst Dinkla on July 18, 2013, 03:59:23 AM
Inventing a testing method of the coating bond that relates to the actual use of prints in our niche of industry may be a better idea than abandon the coated papers in total. It should be possible to do that in DIY style I think. 1000x bending or stretching done on a paper strip printed with a chequerboard black pattern and two scans; one before, one after. Humidity set at 55% in testing. It introduces another factor in the test with only one type of ink applied but could be done quite easily. Make the test as critical as required to divide the worst coated papers from the rest. Or whatever better idea that comes up.

--
Met vriendelijke groet, Ernst

http://www.pigment-print.com/spectralplots/spectrumviz_1.htm
July 2013, 500+ inkjet media white spectral plots.
Title: Re: Inkjet printing on uncoated paper - anyone tried it?
Post by: shadowblade on July 18, 2013, 05:37:10 AM
Inventing a testing method of the coating bond that relates to the actual use of prints in our niche of industry may be a better idea than abandon the coated papers in total. It should be possible to do that in DIY style I think. 1000x bending or stretching done on a paper strip printed with a chequerboard black pattern and two scans; one before, one after. Humidity set at 55% in testing. It introduces another factor in the test with only one type of ink applied but could be done quite easily. Make the test as critical as required to divide the worst coated papers from the rest. Or whatever better idea that comes up.

--
Met vriendelijke groet, Ernst

http://www.pigment-print.com/spectralplots/spectrumviz_1.htm
July 2013, 500+ inkjet media white spectral plots.

You'd also need to add prolonged low humidity, high temperatures, temperature swings and changes in humidity to those tests, as well as exposure to atmospheric pollutants and their byproducts (e.g. acid resistance).

It's an interesting challenge trying to come up with an inkset, RIP and paper combination that gives good photographic results, while being completely idiot-proof for archival durability...
Title: Re: Inkjet printing on uncoated paper - anyone tried it?
Post by: shadowblade on July 18, 2013, 11:57:25 PM
I guess you're asking me amongst others...
I use Ergosoft PosterPrint. Dot gain and absorbancy are dealt with the normal ways.. with light ink limiting, individual channel linearization and limiting. Total ink limiting, K generation, O & G generation, these things also effect those issues and are done in the profiling after the other issues are controlled. Rebalance? Again, that would be taken care of in profiling, over a well linearized and limited paper setup. Dot settings are all totally controllable and also play a role to help minimize mottle and bleed on those kids of papers. No, densities and gamut on Arches, no matter how carefully set up, will not exceed the good coated fine art papers, nor will resolution. For monochrome with Cone inks, all the above applies, but since it's a 2d space, linearization to a chosen output standard is the end of the process, not profiling. But again, all the dot stuff and light ink and max density limiting has to be carefully done to maximize on specialty papers. Getting into more detail about all of this is more like a PosterPrint tutorial and very very few will be interested...
Tyler

I forgot to ask before - does Posterprint let you reassign print heads so that, instead of running each colour through two different heads (i.e. 8 colours in 16 ink cartridges (2 per colour) running through 16 heads), you can run a different colour in each head, for 16 different inks instead of 8?
Title: Re: Inkjet printing on uncoated paper - anyone tried it?
Post by: shadowblade on July 19, 2013, 11:49:40 AM
Inventing a testing method of the coating bond that relates to the actual use of prints in our niche of industry may be a better idea than abandon the coated papers in total. It should be possible to do that in DIY style I think. 1000x bending or stretching done on a paper strip printed with a chequerboard black pattern and two scans; one before, one after. Humidity set at 55% in testing. It introduces another factor in the test with only one type of ink applied but could be done quite easily. Make the test as critical as required to divide the worst coated papers from the rest. Or whatever better idea that comes up.

--
Met vriendelijke groet, Ernst

http://www.pigment-print.com/spectralplots/spectrumviz_1.htm
July 2013, 500+ inkjet media white spectral plots.

Looks like various researchers have beaten me to it:

http://www.dp3project.org/preservation (http://www.dp3project.org/preservation)

Lots of useful articles there.

Bottom line: microporous layers crack very easily due to chemical as well as UV attack, and there's no easy way to restore them once they're cracked. The pigment inks which are printed on them are much more stable than the receptive layers themselves. According to micrographs, the paper base behind the microporous layer remains intact and undamaged. And sealing the back of a photo frame may not be the best idea after all.

I guess uncoated papers are the current solution for longevity after all. Now we just need to work out how to get inkjets to print on them better:

http://www.tappi.org/Downloads/Conference-Papers/2009/09PAPERCON/09pap33.aspx (http://www.tappi.org/Downloads/Conference-Papers/2009/09PAPERCON/09pap33.aspx)
Title: Re: Inkjet printing on uncoated paper - anyone tried it?
Post by: John Nollendorfs on July 19, 2013, 11:59:28 AM

I guess uncoated papers are the current solution for longevity after all. Now we just need to work out how to get inkjets to print on them better:

http://www.tappi.org/Downloads/Conference-Papers/2009/09PAPERCON/09pap33.aspx (http://www.tappi.org/Downloads/Conference-Papers/2009/09PAPERCON/09pap33.aspx)

It's called "solvent inks" ;-)
Title: Re: Inkjet printing on uncoated paper - anyone tried it?
Post by: shadowblade on July 19, 2013, 12:12:25 PM
It's called "solvent inks" ;-)

Don't solvent inks have the same problems with dot gain, bleed and loss of Dmax/saturation as aqueous inks have, when printing on uncoated paper? After all, the only difference is that the pigments are suspended in a hydrophobic solvent mixture (allowing them to stick to vinyl, etc.) rather than a hydrophilic mixture.

Although it's possible to dry some solvent inks faster than some pigment inks, which would help.
Title: Re: Inkjet printing on uncoated paper - anyone tried it?
Post by: Dan Sroka on July 19, 2013, 02:25:18 PM
I print on matte papers exclusively. Sounds like you are considering using art papers, not designed specifically for printing? That I don't do. I stick with matte papers designed for inkjet printers. Canson's Infinity line, for example, has a lot of variety and produces some great results.

But in general, printing on matte papers won't have the same dmax or saturation as with coated -- it is just a different beast. I specifically print on matte papers because I want the results they give me. For example, sure the colors aren't supersaturated, but wow are they soft, subtle and natural looking.
Title: Re: Inkjet printing on uncoated paper - anyone tried it?
Post by: ehackett on July 19, 2013, 02:40:52 PM
This is sort of an odd application, but I was trying to print a photo of two CA missions to match etchings we have of two others, and so matching the paper was the first challenge, then cropping and sizing the photo, and converting to something near the B&W of an etching.  Bottom line:  it worked well but required a bit of trial and error.  The printer and ink--Canon, old i9900--cooperated nicely.  The paper was a watercolor paper bought from Jerry's Artarama...again, trial and error, look and feel...

I really like your project--there is something deeply touching about the possibilities of artisanal papers--and hope you'll post your experiences from time to time.  

Best wishes,

Ed
Title: Re: Inkjet printing on uncoated paper - anyone tried it?
Post by: shadowblade on July 20, 2013, 02:17:55 AM
I print on matte papers exclusively. Sounds like you are considering using art papers, not designed specifically for printing? That I don't do. I stick with matte papers designed for inkjet printers. Canson's Infinity line, for example, has a lot of variety and produces some great results.

But in general, printing on matte papers won't have the same dmax or saturation as with coated -- it is just a different beast. I specifically print on matte papers because I want the results they give me. For example, sure the colors aren't supersaturated, but wow are they soft, subtle and natural looking.

Matte inkjet papers are coated too. The problem isn't whether the paper is glossy, lustre or matte - it's easy enough to adjust gloss with spray, wax or other techniques once the print has been made, and, by doing so, you can increase the Dmax and colour saturation of a matte print to close to that of a glossy print. Put it behind glass (even museum-grade nonreflective glass) and the differences shrink even more. The problem is the inkjet layer itself - it's physically fragile and brittle (essentially being composed of a mixture of sand particles and polyvinyl alcohol binder in a roughly 10:6 ratio) and exposure to UV light and pollutants make it even more so. Pigments themselves may last forever, but that's no good if the layer they're printed on peels or disintegrates - a bit like how prints made a few decades ago on RC paper and kept in dark storage are now outlasting the RC layers they were printed on, or like how platinum prints, although 'indestructible', also catalyse the formation of acids in the paper on which they're printed, causing them to turn brittle and disintegrate.

I'm looking at using uncoated, but sized papers - Arches watercolour, Japanese washi, Indian khadi, some papers by Fabiano. Papers without a surface coating that can crack and peel, but also without a surface coating to facilitate the fast separation of pigment from carrier (to call them 'fast-drying' is a misnomer, since they don't actually dry fast - merely that the ink quickly flows through the microporous layer into the paper substrate, depositing the pigment in the layer as it passes through, so that the pigment is stuck there and no longer bleeds along with the liquid carrier - that's why these papers can outgas for 24 hours or so, as the carrier evaporates). Matte because they don't come in anything else (although you can adjust that later with sprays or wax) and smooth, for better Dmax and saturation.

There's really nothing fundamentally different about printing on uncoated vs coated papers using pigment inks, or any other surface, for that matter. The fundamentals are the same - the ink is low-viscosity so that it can fit through the nozzles on the printhead, the printer sprays it onto the print surface, and, to prevent pigments from spreading or bleeding (either horizontally along the paper surface, causing loss of definition, or vertically through the paper, causing loss of saturation) you need to quickly separate the pigment particles from the liquid carrier. After all, pigments which are no longer together with the carrier can't run or bleed - if you put it in a pen and try to write with it, pure carbon pigment in ink will run and bleed on uncoated paper, but the same pigment won't go anywhere if you apply it with a pencil or crayon. The only difference is that you've rejected one solution to this problem, and need to find another.

Microporous inkjet papers accomplish this separation mechanically - essentially, the microporous layer acts as a 'filter', allowing the liquid carrier to pass straight through, while trapping the pigment particles. But mechanical separation through a filter layer isn't the only way to separate solid pigment from liquid carrier. Evaporation also works - the faster the carrier evaporates, the less the ink can bleed. This depends on temperature, humidity, ink load and the composition of the carrier fluid. Temperature and humidity are easy to control - an inkjet print made at 15 degrees Celcius and 60% humidity will take a while to dry and look distinctly unsharp, but the same print made at 50 degrees Celcius and 20% humidity will dry a lot faster and be much sharper. Ink load can be controlled via the RIP but reducing the ink load also has the effect of reducing Dmax and saturation. You already need a greater ink load on uncoated paper vs coated paper to achieve the same saturation, since some of it will bleed down into the paper, rather than staying on the surface. Which is where heating the paper and ink comes in - at high temperatures, the ink will dry faster, leading to more pigment staying at the surface, and also allowing you to use a larger ink load for the same dot gain, which gives you an even deeper Dmax and saturation. Changing the carrier fluid is the most difficult to customise, and not really an option without some laboratory equipment (e.g. a centrifuge). Solvent vs aqueous inks are an obvious distinction between carrier fluids. But suspending the pigment particles in something like methanol (boiling point 64.7 degrees at sea level) or ethanol (boiling point 78 degrees at sea level) would lead to faster drying times and a sharper print/higher possible ink load, although you'd also have to find a way to keep the ink in suspension while it's in the printer, to avoid clogging. Increasing the pigment load in the ink, or increasing its viscosity, would also work, but would come with clogging problems.

As well as evaporation (already described) and mechanical filtration (already rejected), the other mechanism which can be exploited to separate carrier from pigment, and limit the movement of pigment particles once they have been printed, is adsorption. This is why dye inks don't bleed when printed on microporous surfaces (their longevity due to atmospheric pollutants is another story entirely). Rather than just being carried through the pores into the paper by the carrier, the negatively-charged dye particles are adsorbed to the fumed silica particles in the microporous layer, staying behind while the carrier fluid moves on. This is also how chromatography works, so it's not exactly a new concept. This can also work with encapsulated pigment inks, and is influenced by the composition of the external sizing of the paper. The more the encapsulated pigment sticks to the coating of the paper fibres, the less they will move or bleed. The resin coating on pigment particles in aqueous ink is hydrophobic/oleophilic - a surfactant keeps them in suspension in the ink - while aqueous liquid carriers are hydrophilic, which gives us a mechanism by which we can separate them via adsorption. External sizing used on non-inkjet paper (e.g. gelatin or styrene-acrylate emulsions) are designed to prevent water being absorbed into the paper fibres and the paper becoming soggy. It shouldn't be too difficult to modify this sizing with an additive that will increase the adsorption of resin-coated pigment particles to the coated fibres - already, calcium chloride is showing promise, and some major paper companies are working for bulk office paper. But, again, this requires custom paper (i.e. hiring the services of an independent paper maker willing to make specialty sheets in low volumes) and precludes bulk-buying of existing products in roll form, so it's not for everyone.

Naturally, I'm aiming to print on large sizes, as this minimises the loss of resolution due to the print process (a bit like how postcard-sized dye-sub-on-metal aluminium prints can look unsharp, but large prints look fantastic). An 8x10" or 6x18" print on uncoated paper may look horrible, but the same thing printed at 40x60" or 30x90" could look great. Call it the 'billboard effect', if you will.

I believe the future of printing on uncoated papers will likely be in a combination of modifications to printer design (e.g. preheaters, print heaters and dryers, as currently seen in solvent inkjets) and special uncoated papers with inkjet-receptive sizing, and that the currently-used inkjet-receptive coatings will become less popular for fine art printing, where durability is crucial, as their deficiencies become more apparent, just like RC-coated papers, which are also prone to cracking, and OBA-containing papers, which burn out and change colour, already have.

But, anyway, too much science and not enough printing...
Title: Re: Inkjet printing on uncoated paper - anyone tried it?
Post by: hugowolf on July 20, 2013, 02:46:26 PM
Bottom line: microporous layers crack very easily due to chemical as well as UV attack, and there's no easy way to restore them once they're cracked. The pigment inks which are printed on them are much more stable than the receptive layers themselves. According to micrographs, the paper base behind the microporous layer remains intact and undamaged.

Could you point me to the paper you use to draw this conclusion. I read several but not all of them and the only one that comes close so far was Eugene Salesin and Daniel Burge: “The Cracking of Inkjet Colorant Receiver Layers on Exposure to Light” < http://www.dp3project.org/webfm_send/615>
And in that only two RC papers were used.

Brian A
Title: Re: Inkjet printing on uncoated paper - anyone tried it?
Post by: shadowblade on July 20, 2013, 10:06:03 PM
Could you point me to the paper you use to draw this conclusion. I read several but not all of them and the only one that comes close so far was Eugene Salesin and Daniel Burge: “The Cracking of Inkjet Colorant Receiver Layers on Exposure to Light” < http://www.dp3project.org/webfm_send/615>
And in that only two RC papers were used.

Brian A


When you're looking at the brittleness of the receptor layer itself, it shouldn't matter what kind of paper the layer is attached to, whether it's plain paper or RC, or whether it's printed with ye or pigment.

In any case:

Brittleness of Digital Reflection Prints (http://www.dp3project.org/webfm_send/554) - the 'art papers' (i.e. microporous-coated papers on non-RC paper) and microporous-coated RC papers were the most brittle, and also showed significant anisotropy in brittleness when comparing stresses along the paper as compared with across the paper.

Beyond Lightfastness: Some Neglected Issues in Permanence of Digital Hardcopy (http://www.dp3project.org/webfm_send/549) - the matte microporous inkjet paper was the equal worst in terms of showing macroscopic cracking or buckling, together with glossy silver gelatin paper (i.e. baryta paper, which is known to be fragile). In addition, all the porous surfaces, unlike the others showed micro-cracking under the microscope even when there was no macroscopic cracking present, which was not apparent in the other papers.

Further Observations of Ozone and Nitrogen Dioxide Pre-Dosed Digital Prints Over Time (http://www.dp3project.org/webfm_send/706) - microporous coatings all showed extensive cracking and delamination following exposure to nitrogen dioxide and/or ozone. Obviously, this doesn't happen in uncoated papers, since there's no layer to crack. All the papers yellowed, too; however, there was no indication of whether these papers were buffered or not (buffering would help slow the yellowing of the paper, but would do nothing for the cracking of the surface) or whether they contained OBAs.

The Cracking of Inkjet Colorant Receiver Layers on Exposure to Light (http://www.dp3project.org/webfm_send/615) - these tests were performed on RC-coated papers; however, we're talking about what happens to the inkjet receptive layer here, not what happens to the underlying paper. They all cracked or disintegrated with less than 100 megalux-hours of exposure to xenon light, or 2 weeks of exposure to ozone at 5ppm. There was no difference in this behaviour whether paper was unprinted, printed with dye or printed with pigment. One of the papers also exhibited cracking at the start point even at quite a large diameter, which really points to the fragility of these papers. The cracking became even worse upon exposure to light and ozone.

Title: Re: Inkjet printing on uncoated paper - anyone tried it?
Post by: hugowolf on July 21, 2013, 01:14:19 AM
It would be really difficult to draw any conclusions about real world situations based on these papers. Two of the papers you cite involve basically folding the paper, something that would generally suggest the need for a reprint anyhow. Ozone and nitrogen dioxide in sealed aluminium bags is another ‘when is this going to happen the real’ situation – high levels of pollutants is not a parallel to accelerated light testing.

The last paper is more interesting, but with only two papers tested, and very different problems occurring with each, there is room for further study. Could there be ink receptive coating where there are no problems? Could there be ink receptive coatings where different problems arise?

Brian A
Title: Re: Inkjet printing on uncoated paper - anyone tried it?
Post by: shadowblade on July 21, 2013, 02:50:08 AM
It would be really difficult to draw any conclusions about real world situations based on these papers. Two of the papers you cite involve basically folding the paper, something that would generally suggest the need for a reprint anyhow.

Actually, from a mechanical point of view, this test is a perfectly valid and well-documented means to assess brittleness, and not just in paper. Essentially, what it's testing is differences and changes in the stress-strain characteristics of the layer, by determining the degree of deformation (not the force required) to stress it to breaking point. Obviously, you wouldn't fold the paper or roll it up into a tiny roll in real life. But what the tests do tell us is how susceptible each coating is

And, from a binary point of view (coated vs uncoated, cracking vs non-cracking) it gives a pretty clear result - namely, that microporous coatings have the potential to crack, and crack fairly easily, while uncoated papers, with no such layer, obviously cannot crack, since there's no layer to crack in the first place.

Quote
Ozone and nitrogen dioxide in sealed aluminium bags is another ‘when is this going to happen the real’ situation – high levels of pollutants is not a parallel to accelerated light testing.

It's not exactly the same, but it's the closest thing we've got, apart from actually waiting two hundred years and seeing what happens!

Quote
The last paper is more interesting, but with only two papers tested, and very different problems occurring with each, there is room for further study.

Definitely. But it works as a pilot study, suggesting that inkjet prints on coated paper are not likely to last as long as print permanence studies may suggest, because of the physical and chemical durability of the receptive layer, independent to the permanence of the inks used.

Quote
Could there be ink receptive coating where there are no problems? Could there be ink receptive coatings where different problems arise?

Possibly - but it's hard to say. You'd need a test involving a larger number of papers and coatings to determine that. Certainly, papers with a baryta layer are out (baryta layers are brittle and notoriously fragile, and have been around for long enough for this to be verified) as are RC papers (which tend to disintegrate over around 40 years in real use). It would be *very* nice to find an inkjet receptive coating without these vulnerabilities. It'd have to be flexible, and move with the paper. I believe there are some self-binding silica and ceramic layers out there, which stick together, repairing cracks and microcracks and not requiring any PVA binder, but they exhibit the problem of silica or ceramic particles migrating out of position as the paper flexes slightly over time - that is, the surface doesn't crack, but the pigment-coated silica particles move, causing a gradual blurring and loss of definition in the image. Also, they don't bind as strongly to the paper as the PVA-containing layers.

In the end, I guess how conclusive these papers are depends on what sort of conclusions you're trying to draw. If you're trying to work out which coating is better than which other coating, whether spray-on protection prevents cracking, whether future coatings can fix this or anything like that, they're not particularly conclusive, although they are a good start indicate that further research is needed. If you're just trying to determine whether coatings crack, or how easily they generally crack, and whether UV light or pollutants accelerate this degradation, in order to decide whether to print archival works on current coated or uncoated stock, I'd say it's fairly conclusive and useful information.
Title: Re: Inkjet printing on uncoated paper - anyone tried it?
Post by: hugowolf on July 21, 2013, 03:10:44 AM
... I'd say it's fairly conclusive and useful information.

Conclusive no, useful yes.

If you continue with this vein, it would be interesting to see which uncoated papers work and which do not. At art school there was a list given out of this very information, long lost unfortunately.

Clearly the sizing matters a great deal. Papers designed for pastel, crayon, chalk and charcoal, graphite, etc, will probably not work out. Traditional printing papers like Rives BFK should, along with more heavily sized watercolor papers, should be excellent candidates.

Brian A
Title: Re: Inkjet printing on uncoated paper - anyone tried it?
Post by: shadowblade on July 21, 2013, 04:30:15 AM
Conclusive no, useful yes.

If you continue with this vein, it would be interesting to see which uncoated papers work and which do not. At art school there was a list given out of this very information, long lost unfortunately.

Clearly the sizing matters a great deal. Papers designed for pastel, crayon, chalk and charcoal, graphite, etc, will probably not work out. Traditional printing papers like Rives BFK should, along with more heavily sized watercolor papers, should be excellent candidates.


Brian A


Which brings me to my next point, which I forgot to type before I went out for lunch, but which I sort of hinted at in an earlier post (http://www.luminous-landscape.com/forum/index.php?topic=80179.msg649323#msg649323).

Basically, to prevent ink from bleeding, losing sharpness, saturation and Dmax, you must separate the pigment from the solvent, so that the pigment stays in place and doesn't move anywhere. You can do this by filtering out the pigment while letting the solvent run through (this is what microporous coatings do), by evaporating the solvent quickly so that it doesn't have time to spread (heating elements in solvent printers) or by using a chemical adsorption process whereby the pigment particles - or, more correctly, the resin coating encapsulating them - are electromagnetically held in place by something in the paper, thereby not moving as much while the solvent moves on.

Apart from the application of heat and removal of atmospheric moisture to encourage evaporation, the other methods all require some sort of coating. So do watercolour paints and traditional printing, for that matter - you don't want ink or pain soaking into, then bleeding along, the paper's fibres. But there's no rule saying that the coating must be in a form of a (relatively) thick, brittle coating on the surface. The required coating to prevent water absorption in watercolour paints is applied as a thin layer over the individual fibres, in the form of sizing. It's very flexible because of its extreme thinness, and moves with the paper. There's no reason that a hydrophobic adsorptive layer can't be applied as part of the sizing process, repelling the aqueous solvent while adhering to the hydrophobic resin coating of the pigment particles. And this would be as flexible as the paper is (being a component of it) and could never delaminate or crack. As a side effect, it would also help protect the paper from moisture and atmospheric pollutants, since pollutants tend to dissolve to form aqueous acids, which then attack the paper.

This is where I believe the future of inkjet papers and coatings lies - not in a thick coating that's essentially separate from the paper onto which it is layered, but as a component and an essential step of the manufacture of the paper itself.
Title: Re: Inkjet printing on uncoated paper - anyone tried it?
Post by: Ernst Dinkla on July 21, 2013, 07:40:34 AM
It would be really difficult to draw any conclusions about real world situations based on these papers. Two of the papers you cite involve basically folding the paper, something that would generally suggest the need for a reprint anyhow. Ozone and nitrogen dioxide in sealed aluminium bags is another ‘when is this going to happen the real’ situation – high levels of pollutants is not a parallel to accelerated light testing.

The last paper is more interesting, but with only two papers tested, and very different problems occurring with each, there is room for further study. Could there be ink receptive coating where there are no problems? Could there be ink receptive coatings where different problems arise?

Brian A


It would be nice to see a meaningful correlation between Aardenburg's testing (lumen or energy or whatever per square inch) and the RIT tests on the coating longevity to see what goes first and then evaluate the relation to known print behaviour in the past like that of silver halide B&W prints, chromogenic color prints etc. If that is possible. Three institutes, Wilhelm-Research, Aardenburg Imaging, Image Engineering did select other sources of illumination for the fade resistance tests. Xenon gives fast results that are harder to extrapolate to real world conditions.

It is not that I do not see issues with the coating structure and their bond to the paper base. I have written before that I do see possible issues there, I have warned about fast decurling methods on thin cores for the same reason. The main thing is that we get acceptable compromises, balanced to real world conditions. A brick can be thrown on any print, 1500 year old stone Buddhas are dynamited, paintings end in the furnace in Eastern Europe. I do not see a reason to use media that can withstand assaults like that.

--
Met vriendelijke groet, Ernst

http://www.pigment-print.com/spectralplots/spectrumviz_1.htm
July 2013, 500+ inkjet media white spectral plots.
Title: Re: Inkjet printing on uncoated paper - anyone tried it?
Post by: shadowblade on July 21, 2013, 08:10:13 AM
It would be nice to see a meaningful correlation between Aardenburg's testing (lumen or energy or whatever per square inch) and the RIT tests on the coating longevity to see what goes first and then evaluate the relation to known print behaviour in the past like that of silver halide B&W prints, chromogenic color prints etc. If that is possible. Three institutes, Wilhelm-Research, Aardenburg Imaging, Image Engineering did select other sources of illumination for the fade resistance tests. Xenon gives fast results that are harder to extrapolate to real world conditions.

What makes it even more difficult is the fact that porous coatings exhibit some cracking under the microscope even fresh out of the printer. It really doesn't take a lot to make these micro-cracks appear. And, even if stored in complete darkness (but with real-world humidity and temperature variation) they will continue to degrade, due to the mechanical stresses caused by differential expansion on the microscopic level. Any handling whatsoever - moving the frame, for instance - will only make it worse.

With black-and-white prints, one can certainly say that the coating will fail first - pure carbon pigments are essentially immutable at room temperature. With colour prints, it's harder to say, but the failure after just 100 megalux hours under xenon doesn't seem promising. Don't forget, Aardenburg limits are for 'noticeable' fading, not for complete fading - a good-quality pigment print will last a lot longer than the 100, 150 or 200 Mlux hours tested; those inks which contain a mixture of dye and pigment, such as Epson Ultrachrome, will even start to fade more slowly after the dye inks have faded and only the pigments are left.

Quote
It is not that I do not see issues with the coating structure and their bond to the paper base. I have written before that I do see possible issues there, I have warned about fast decurling methods on thin cores for the same reason. The main thing is that we get acceptable compromises, balanced to real world conditions. A brick can be thrown on any print, 1500 year old stone Buddhas are dynamited, paintings end in the furnace in Eastern Europe. I do not see a reason to use media that can withstand assaults like that.

Obviously you can't protect against intentional damage, or things like fire or flood which would destroy most things. But I'd like to produce products that, in the absence of disaster such as fire or flood, and with a reasonable level of care (not necessarily museum care, but the kind of care that would be expected of an old family photo, or great-grandma's wedding album in platinum, for example) will last essentially forever.
Title: Re: Inkjet printing on uncoated paper - anyone tried it?
Post by: Ernst Dinkla on July 21, 2013, 09:45:19 AM
Exposure in Aardenburg or Wilhelm tests so far did not show inkjet coating falling off spontaneously I guess or we would have heard it. Plastered walls of many buildings can withstand time over long periods, whether interior and exterior. I am sure there will be cracks at macro and micro level from day one in both cases. Images that will last forever do not exist. Somewhere (even) you have to find a compromise in print making. For me it should be beyond the best processes of black and white silver halide prints of the past for digital black and white and on a mechanical level similar longevity for digital color prints. Any progress in color fade resistance of inkjet inks is welcome but we are already beyond the color longevity of several color processes of the past. There are methods/materials/equipment you describe that I do not see as real world substitutes for the systems we have today. I do not see 12 coats of gloss varnish on a matte print as an acceptable alternative for gloss inkjet printing today. Not in the effort it needs or the complications it could create in longevity, among them yellowing and flexibility/bond in time. There are images/artists that will find the uncoated paper prints as the best expression of their creativity but right now that group will be small compared to photographers and artists in general.

There have been efforts and there will be efforts to create papers that have no or thinner coatings to achieve what you are aiming at. HP's Color Lok or infusion methods developed by the late John Edmunds and other scientists. In the industrial web inkjet printing industry new substrates are in development every day now. Any paper manufacturer whether it is Felix Schoeller, Mitsubishi or one of the Scandinavian conglomerates, they all are busy to make better inkjet papers for inkjet web presses for various reasons: image quality improvement, printing speed, costs. If good, spin-offs will be brought to our niche of the market. I use an offset paper Biotop 3 on a customised officeprinter that already gives good image quality with a customised HP MK and PK quad set, there is an industrial grade of that paper made with even more inkjet compatibility. For me one goal was finding a substitute for rotogravure printing at its heyday in the 1960's. A modest goal if I put the prints next to prints on Photorag etc but they come close to the rotogravure prints I like.

On the Digital B&W list much more has been discussed on uncoated papers used for inkjet printing. I mentioned Paul Roark, Tyler has written here already, there have been more. There were contributions by an Italian who showed some tenacity on the subject. Your messages reminded me of him. http://www.mantinieri.com/techniques.html  Gelatine is his remedy. Varnishes like aliphatic polyurethanes have been tried. Mayer rods purchased or wound in DIY style for the application of varnishes. There is a 15 year period of user experiments since the Epson 3000/1500 appeared and another decade before that with Iris printers. It started with uncoated papers and it may end with "uncoated" inkjet papers.

When printer users today push a button on the printer they get a quality way beyond the inkjet prints of 15 years ago. Much is contributed by the industry, much has been tried out by savvy users that became standards for others and the inspiration for the printer manufacturers. Many printer users did not neglect that last step in print making but showed extraordinary skills to make the best of what was available. There have been visionary people along that path that were successful but not all of them achieved that. It is not difficult to find what the flaws are of today's inkjet printing but it is much harder to solve them in practice.

--
Met vriendelijke groet, Ernst

http://www.pigment-print.com/spectralplots/spectrumviz_1.htm
July 2013, 500+ inkjet media white spectral plots.
Title: Re: Inkjet printing on uncoated paper - anyone tried it?
Post by: MHMG on July 21, 2013, 11:06:43 AM
Many good points and thoughtful remarks in this thread. That said, It is well known that both natural and synthetic organic coatings can crack (natural resins like damar,  shellac, gelatin, and more modern ones as well like PE, PVA, PVB etc. etc). Some coatings have been applied in ways that make them highly sensitive to microcracking, and/or delamination, but these and others have also been applied in ways that allow the artwork to be enjoyed for centuries. Environmentally induced mechanical stresses that lead to microcrack formation, crack propagation, and in extreme instances coating delamination was a huge part of the research I conducted with colleagues when I was at the Smithsonian institution. I was personally interested in low temperature storage of color photographs and films made on acetate and nitrocellulose base to save these works from thermally induced degradation which can occur at an alarming rate at normal room temperature. Low temperature storage and return to use/display environments forces a temp/humidity cycle and thus induces some stresses on the objects. Could the art tolerate the stress cycling better than the thermal degradation that would occur in steady room temperature storage? That was my concern, and to find a technically sound answer required a rigorous scientific approach. Similarly, my colleagues were interested in environmentally induced cracking of traditional paint and varnish coatings on canvas, wood, etc. Our research group thus tackled these environmental and material structure issues to better understand the role of low (i.e."flatlined") versus moderate versus wide temperature/humidity cycles within the Museum environment and how detrimental fluctuations were to the chemical and structural safety of paintings and photographs. As the research progressed we were able to successfully model the mechanical response of paintings and photographs to changes in temperature and humidity using modern engineering programs and finite element analysis, and we demonstrated that there is indeed an elastic regime where paintings and photographs can cycle indefinitely without being at risk. It was very controversial research at the time because it showed that very tight environmental controls being recommended at the time could be safely relaxed to the point where huge energy savings would accrue, ie., that perfect "flatlined" humidity and temperature offered no superior safety over environments that were allowed to swing between 35-60%RH.  Today this research has been vindicated and indeed embraced under new "green energy" initiatives being advocated today in the museums and archives community. I mention all this to back up my confidence that not all inkjet coated media are going to fail so catastrophically as the IPI results would seem to suggest.

The cited IPI article is a non peer-reviewed paper with an agenda, IMHO. The researchers deliberately selected just two undisclosed inkjet papers out of hundreds on the market, and they ran a primitive strain-to-break tensile test (there are much better ways to measure and the elastic/plastic deformation characteristics) where even the control samples "failed" at some vaguely measured value in order to demonstrate that inkjet coatings can crack. The conclusions based on just two non randomly selected samples is somewhat pathetic, IMHO, but I will cut IPI some slack by reminding myself how IPI typically approaches its primary audience. IPI's audience is comprised of many librarians, archivists, and conservators who anxiously look upon inkjet media today as some new and mysterious medium they are now beginning to have to deal with in their professions. So, to show a picture of a cracked or delaminated inkjet print, whether by inducing a failure in the lab or finding a real-world example, is indeed informative to this group at a very simplistic level.  What the research fails to do give us is a proper context for better understanding the extent of the problem in real world use. More research is needed and with a much better design-of-experiment methodology. I've still got access to my colleagues (they are now retired but still active) and the equipment needed to conduct this type of research. What I don't have is the funding, and grants are only given to non-profit institutions like IPI, so again, it comes down to a funding bottleneck for me to start this work. But I do think it's perhaps the most important initiative after light fastness research to undertake on modern media, and I am trying to think outside the box on ways to be able to accomplish this research.

cheers,
Mark
http://www.aardenburg-imaging.com
Title: Re: Inkjet printing on uncoated paper - anyone tried it?
Post by: MHMG on July 21, 2013, 11:43:15 AM
Btw, I was working on an R&D project a couple of years ago (private consulting work that doesn't appear on the AaI&A website is how I survive financially) that involved exactly what Shadowblade and others have suggested would be great, namely, an internally sized paper that gives increased color gamut and well controlled bleed for aqueous inkjet. The R&D was being undertaken by a major US paper manufacturer of very high quality cotton and cotton blend papers. The project got as far as a trial production lot.  I sent some samples of it for independent feedback to some fine art printmakers whose skills and experience I respect very much. Tyler B was one of those printmakers, and he's following this thread, so perhaps he can weigh in on what his impressions of this paper were like. The feedback overall was mixed. Some thought it was really cool stuff, others thought "what's the point"?.  I personally thought it had great potential and some very subtle properities that I had not seen in other coated or uncoated media, and that with some tuning/tweaking at the sizing bath on the production line, we'd get to where it needed to go.  However, although this specially infused paper surpassed many performance levels of other high quality non coated papers including bleed control, color gamut, and dmax, it fell a little short on dmax and color compared to many of today's premier coated fine art papers (e.g., HN photo rag). So, the manufacturer discontinued the R&D because the marketing folks couldn't foresee enough return on investment for a paper that would likely become a niche product within an already niche market. Nonetheless, I was personally able to produce some really beautiful prints on this paper, so I urged the management to keep working on it a little longer.  Perseverance was key. The marketing folks won the argument. The program was abandoned. All of which reminds me of one of my favorite sayings: "Confidence is what you have before you know the full extent of the situation" :)

cheers,
Mark
http://www.aardenburg-imaging.com
Title: Re: Inkjet printing on uncoated paper - anyone tried it?
Post by: TylerB on July 21, 2013, 04:58:46 PM
Hi Mark, I liked the paper and still have a large quantity of it that was gifted to me for a potential project. Due to it being thin, and printable on both sides, I thought it perfect for custom artist produced limited edition books, and my friend Lauren at velanoche.com, heavily involved in such projects, was very enthusiastic as well. We hoped to be able to spread the word.
I think it's nearly impossible these days to launch a viable and successful product that addresses an unconventional niche user base, particularly in the arts in this economy. This paper did not have the precious object appeal of the traditional uncoated papers, lush surface, thickness in the hand, and natural deckles. Conversely it also did not have the visual impact from high gamut and dmax of the papers most popular with many photographers. It was somewhere in between.
The tradeoff for that compromise is subtlety over flash, never easy to sell, and promise of a paper technology addressing longevity concerns. You of all people know how hard it has been to get support for that issue amongst this community (or any), who should care to most.
Of course due to larger circumstances you know doubt are aware, the project went away. I'm saving my batch for something special. I'd like to think the existence of that paper means the concept may ignite further development somewhere.
Tyler
Title: Re: Inkjet printing on uncoated paper - anyone tried it?
Post by: shadowblade on July 21, 2013, 05:57:17 PM
Btw, I was working on an R&D project a couple of years ago (private consulting work that doesn't appear on the AaI&A website is how I survive financially) that involved exactly what Shadowblade and others have suggested would be great, namely, an internally sized paper that gives increased color gamut and well controlled bleed for aqueous inkjet.

Internally-sized, or externally-sized? I thought the nature of the internal sizing didn't really matter much - as long as it was present - as the main role of the internal sizing is to prevent water absorption into the fibres and the deformation of individual fibres.

Quote
The R&D was being undertaken by a major US paper manufacturer of very high quality cotton and cotton blend papers. The project got as far as a trial production lot.  I sent some samples of it for independent feedback to some fine art printmakers whose skills and experience I respect very much. Tyler B was one of those printmakers, and he's following this thread, so perhaps he can weigh in on what his impressions of this paper were like. The feedback overall was mixed. Some thought it was really cool stuff, others thought "what's the point"?.  I personally thought it had great potential and some very subtle properities that I had not seen in other coated or uncoated media, and that with some tuning/tweaking at the sizing bath on the production line, we'd get to where it needed to go.  However, although this specially infused paper surpassed many performance levels of other high quality non coated papers including bleed control, color gamut, and dmax, it fell a little short on dmax and color compared to many of today's premier coated fine art papers (e.g., HN photo rag). So, the manufacturer discontinued the R&D because the marketing folks couldn't foresee enough return on investment for a paper that would likely become a niche product within an already niche market. Nonetheless, I was personally able to produce some really beautiful prints on this paper, so I urged the management to keep working on it a little longer.  Perseverance was key. The marketing folks won the argument. The program was abandoned. All of which reminds me of one of my favorite sayings: "Confidence is what you have before you know the full extent of the situation" :)

cheers,
Mark
http://www.aardenburg-imaging.com

Out of interest, what sort of paper was it? Was it a thick, 300gsm-or-so art paper, was it a thin copy paper, or something in between? What was the texture like? 'Plasticky', or did it feel like a high-quality paper?

The thing is, I wouldn't see the development of an inkjet-receptive sizing process as a niche product. Fine-art papers with an emphasis on longevity rather than pure Dmax are certainly niche - even so, it was a preliminary study, as you said, with room for further improvement, and, once gallery and museum curators and conservators of national archives learn of a super-archival product like that, they would likely start preferring work printed on it. But that's only a secondary product to the main deal - that is, archival copy paper for documents. Company documents, medical records, government documents, just to name a few which must stand the test of time, and often require both electronic and paper backups. I've seen far too many medical records that, although just ten to fifteen years old and kept in medical archives, have faded almost to the point of illegibility (due to laser printer or photocopier toner rubbing off) or which have started disintegrating (being printed on copy paper, rather than acid-free archival paper). On the other hand, I've seen 100-year-old medical records and medical letters handwritten on quality paper that still look almost brand-new, save a slight yellowing of the underlying paper.

Obviously, a fine-art paper with these characteristics will not have huge sales, although, as a niche product which will obviously be used for high-value, archival artworks, each sheet could sell for significantly more than the coated papers of today. It would also be useable by watercolour painters and other non-digital artists since, as well as being an inkjet paper, it's also a well-sized, stable paper that doesn't get soggy - just that the sizing happens to be inkjet-receptive. The thing is, all high-quality paper used for printing has to be sized somehow. This goes for office paper (especially that used for documents which must have a certain lifespan) and hardcover books - two major users of paper. So, a new sizing that works for these processes, as well as inkjet printing (since an ever-increasing number of things are printed by inkjet) could potentially be used by all sized papers.

But, ultimately, I believe this is something that will be developed either by a small, independent fine-art paper maker, selling to people who know exactly what they are looking for and who are willing to pay high prices for a paper with those characteristics, or by a large paper company (e.g. Reflex) specialising in copy paper for office use. It will not be developed by Canson, Hahnemuhle or another large art-paper manufacturer, who have insufficient incentive to develop it (since many people who buy their papers buy them for immediate visual impact, or just because they've heard good things about the brand, and won't pay extra-high prices for specialty paper), to whom the development costs are substantial (being medium-sized companies catering to a relative niche) and to whom the risk of failure is too great (they have too much to lose by trying it). Much easier to market 'eco-paper' made from recycled elephant dung to people who will buy it just for what it's made from, forgetting the fact that elephant dung is basically just lignin-containing cellulose derived from trees that has been crushed, mangled and subjected to highly acidic conditions in the elephants' digestive tracts...
Title: Re: Inkjet printing on uncoated paper - anyone tried it?
Post by: shadowblade on July 21, 2013, 06:26:21 PM
Many good points and thoughtful remarks in this thread. That said, It is well known that both natural and synthetic organic coatings can crack (natural resins like damar,  shellac, gelatin, and more modern ones as well like PE, PVA, PVB etc. etc). Some coatings have been applied in ways that make them highly sensitive to microcracking, and/or delamination, but these and others have also been applied in ways that allow the artwork to be enjoyed for centuries. Environmentally induced mechanical stresses that lead to microcrack formation, crack propagation, and in extreme instances coating delamination was a huge part of the research I conducted with colleagues when I was at the Smithsonian institution. I was personally interested in low temperature storage of color photographs and films made on acetate and nitrocellulose base to save these works from thermally induced degradation which can occur at an alarming rate at normal room temperature. Low temperature storage and return to use/display environments forces a temp/humidity cycle and thus induces some stresses on the objects. Could the art tolerate the stress cycling better than the thermal degradation that would occur in steady room temperature storage? That was my concern, and to find a technically sound answer required a rigorous scientific approach. Similarly, my colleagues were interested in environmentally induced cracking of traditional paint and varnish coatings on canvas, wood, etc. Our research group thus tackled these environmental and material structure issues to better understand the role of low (i.e."flatlined") versus moderate versus wide temperature/humidity cycles within the Museum environment and how detrimental fluctuations were to the chemical and structural safety of paintings and photographs. As the research progressed we were able to successfully model the mechanical response of paintings and photographs to changes in temperature and humidity using modern engineering programs and finite element analysis, and we demonstrated that there is indeed an elastic regime where paintings and photographs can cycle indefinitely without being at risk. It was very controversial research at the time because it showed that very tight environmental controls being recommended at the time could be safely relaxed to the point where huge energy savings would accrue, ie., that perfect "flatlined" humidity and temperature offered no superior safety over environments that were allowed to swing between 35-60%RH.  Today this research has been vindicated and indeed embraced under new "green energy" initiatives being advocated today in the museums and archives community. I mention all this to back up my confidence that not all inkjet coated media are going to fail so catastrophically as the IPI results would seem to suggest.

I guess it comes down to what risk of failure you're willing to accept. For general-edition prints, I have no problem printing them on coated papers - I particularly like Hahnemuhle Photo Rag Pearl and Silver Rag. They'll look great on display, but I have no expectation that they'll last more than fifty years of real display. For limited-edition prints and special works (e.g. for galleries or certain institutions), however, I'd prefer to eliminate as many things as possible which can fail - the institutions to which these are sold may have been in existence for hundreds of years, and these items are the sort that are likely to be passed down generation to generation, or belong to a collection.

Quote
The cited IPI article is a non peer-reviewed paper with an agenda, IMHO. The researchers deliberately selected just two undisclosed inkjet papers out of hundreds on the market, and they ran a primitive strain-to-break tensile test (there are much better ways to measure and the elastic/plastic deformation characteristics) where even the control samples "failed" at some vaguely measured value in order to demonstrate that inkjet coatings can crack. The conclusions based on just two non randomly selected samples is somewhat pathetic, IMHO, but I will cut IPI some slack by reminding myself how IPI typically approaches its primary audience. IPI's audience is comprised of many librarians, archivists, and conservators who anxiously look upon inkjet media today as some new and mysterious medium they are now beginning to have to deal with in their professions. So, to show a picture of a cracked or delaminated inkjet print, whether by inducing a failure in the lab or finding a real-world example, is indeed informative to this group at a very simplistic level.  What the research fails to do give us is a proper context for better understanding the extent of the problem in real world use. More research is needed and with a much better design-of-experiment methodology. I've still got access to my colleagues (they are now retired but still active) and the equipment needed to conduct this type of research. What I don't have is the funding, and grants are only given to non-profit institutions like IPI, so again, it comes down to a funding bottleneck for me to start this work. But I do think it's perhaps the most important initiative after light fastness research to undertake on modern media, and I am trying to think outside the box on ways to be able to accomplish this research.

cheers,
Mark
http://www.aardenburg-imaging.com


I guess it depends on what conclusions you're trying to draw. Certainly, you can't draw any definitive conclusions about which coatings are better than others, exactly how they fail, or how long you should expect the coatings to last in real-world display. But the only conclusion I'm trying to reach in this case is, 'current inkjet receptive coatings can crack and fail and brittleness is increased by exposure to UV light and pollutants, whereas there is no layer on uncoated papers that can potentially fail' - and these preliminary tests illustrate it perfectly.

More tests are certainly needed, though, in order to find a solution.
Title: Re: Inkjet printing on uncoated paper - anyone tried it?
Post by: MHMG on July 21, 2013, 08:43:32 PM
... whereas there is no layer on uncoated papers that can potentially fail' - and these preliminary tests illustrate it perfectly.


true, but that doesn't mean uncoated papers don't embrittle upon exposure to light, heat, humidity, etc, and uncoated papers can discolor uniformly or with uneven spot patterns (foxing),  tear or disintegrate, and are often very susceptible to mould and mildew owing to the traditional sizings used like starch or gelatin.  Moreover, the possible risk of a coating failure is often outweighed by other durability factors imparted by a coating to the paper substrate.  For example, I've seen many examples of foxing on old prints made on uncoated paper... Nasty Brown spots randomly showing in an image due to localized degradation within the sized paper which are typically more visually disconcerting than a few minor cracks in an otherwise unaffected coating.  In contrast, I've never seen foxing of any kind on baryta coated papers.  A durable coating often hides sins of deterioration going on in the paper base or on the mount board of vintage photographs.

Like others, I have a great personal interest in improved inkjet printing on uncoated papers, but I'm not ready to abandon coated papers. They serve a need, and they can be very durable and long lasting if one chooses wisely. Your 50 year expectation for longevity of all coated papers is unnecessarily pessimistic.  Btw, HN Photo Rag Pearl is a personal favorite of mine as well. The coatings on Photo Rag Pearl and Photo Rag Satin are quite unique, less prone to cracking than other luster and satin inkjet media, and both are very forgiving when spraying with a protective spray like Premier Print Shield, HN Protective Spray, etc. They tolerate two or three coats with little alteration to the surface texture and luster of the inkjet receptor coating, yet differential gloss and bronzing are eliminated.  IMHO, other vendors don't have comparable offerings to these two papers.



regards,
Mark
Title: Re: Inkjet printing on uncoated paper - anyone tried it?
Post by: hugowolf on July 21, 2013, 11:24:56 PM
You have to remember that some printing processes are very different from inkjet printing. The main traditional reason for internal sizing is to prevent bucking under heavy aqueous application. And some fine art printing processes involve soaking the paper before impression: ie mezzotint, where it can take days, if not weeks for the paper to dry after printing. A good cotton paper can take a long time to dry out.

The idea of internal sizing is to preserve the dimensions of the paper, so when it has dried, it is somewhat similar in dimension to its former state. It isn’t just a prevention of dot (or line) gain.

Prepared papers are not a new thing, they have been in existence for several centuries. Surface preparation is not something new.

Brian A
Title: Re: Inkjet printing on uncoated paper - anyone tried it?
Post by: shadowblade on July 21, 2013, 11:31:48 PM
You have to remember that some printing processes are very different from inkjet printing. The main traditional reason for internal sizing is to prevent bucking under heavy aqueous application. And some fine art printing processes involve soaking the paper before impression: ie mezzotint, where it can take days, if not weeks for the paper to dry after printing. A good cotton paper can take a long time to dry out.

The idea of internal sizing is to preserve the dimensions of the paper, so when it has dried, it is somewhat similar in dimension to its former state. It isn’t just a prevention of dot (or line) gain.

Prepared papers are not a new thing, they have been in existence for several centuries. Surface preparation is not something new.

Brian A

That's internal sizing. External sizing is quite different.