Alternative to Print Shield for coating prints

[Frodo]

I mount my black and white prints on MDF because glass hides the lovely texture of Epson cold press natural and similar papers.

It seems that Print Shield is one of the preferred coating sprays (http://www.ecoprintshield.com/coating-with-printshield/)
However, I have been unable to obtain that in New Zealand.

Does anyone have any experience with N.A.M. Matt Spray (http://www.nationalart.com.au/product/n-a-m-matt-spray/)?
The link describes this as "Permanent protection for photographs, prints, artwork and most transfer lettering. Helps protect from U.V. and reduces glare on glossy surfaces".

Thanks, Bob

[Jeff-Grant]

Is this what you are after:https://www.iphoto.net.au/premier.aspx

[Frodo]

Yes, that's the stuff I'd like to get, but found it difficult to get here.  The local Photo Warehouse advertises it on their website, but no longer stocks it.
Aerosols can't be shipped by air, so I found the Matt Spray at a local art supplies dealer.  $19 compared to $45, so is also a lot cheaper.  But it has to work!
Thanks, Bob

[Jeff-Grant]

They had an NZ online link but I guess that it must be shipped from Oz.

[Ernst Dinkla]

Hahnemúhle Sprays?  Considered to be the same as the Premier product.

for NZ;

https://www.u-buy.co.nz/brand/Hahnemuhle

https://www.hahnemuehle.com/en/contact/distributors-world-wide.html

Do not use matte sprays if you search for alternatives. Gloss sprays with small particles penetrate the paper and ink better so the image stays matte without losing Dmax etc which is not the case with matte varnishes. Slower evaporating varnishes work better too. Despite the odor (white spirit dissolved acrylic) the Talens 680 protective varnish is quite good. With all be aware that higher temperatures can harden the varnish faster and give an uneven image surface quality.

Met vriendelijke groet, Ernst

http://www.pigment-print.com/spectralplots/spectrumviz_1.htm
March 2017 update, 750+ inkjet media white spectral plots

[Paul Roark]

Be sure to distinguish between the solvent base aerosol Print Shield and the water based Eco products.  I use the solvent based Print Shield regularly for glossy prints (papers and canvas) to protect them when mounted un-glazed.  With matte paper, however, the solvent based Print Shield offers some protection, but it is not equal to the protection the water based Eco Print Shield or similar coatings can give.  I do not consider  the matte paper/canvas prints to be adequately protected by the solvent sprays for un-glazed display.   

With the water based products, which are really needed for matte papers to be well protected if un-glazed, unless you have a HVLP sprayer and dust free spray  booth, you're going to be stuck applying the coating with a roller.  I have not had much luck getting a totally even coating with that form of application. 

For un-glazed display I recommend most people stick with glossy papers and canvases that can be sealed with the solvent based Print Shield.  It's easy to get an even coating, and it dries quickly enough that dust is not much of a problem even if, like me, an open garage is what has to serve as a "spray booth."

Note that with canvas, because the solvent based spray dries rather brittle, it cannot be stretched after sprayed and thoroughly dried.  Even if sprayed after stretching, the solvent based sprays could be a problem if the canvas ever needs to be re-stretched due to sagging.  I mount canvas on acid free foam core, in part, for this reason.  I can then spray the glossy canvas  (high dmax and fine weave of Innova IFA Fiba Print Ultra Gloss) with solvent based Print Shield easily without concern for the problems of cracking coating or sagging with time.

Paul
www.PaulRoark.com

[dgberg]

Paul has it all right.

Cost is the only thing not discussed. At  $16.95 more or less for a 12 oz. can I get a little over 1 sq. foot of coverage per oz.
with two moderate coats. That is $1.40 per square foot (1 oz.)or most times as much as your paper cost.
I use the small cans but very sparingly. You can buy it by the gal for around $1.00 per ounce. (+or-)
Some here have tried the crystal clear Krylon with good results. A little less then half the cost of Print Shield at $7.28 for 11 oz.
Would want to do some testing before using it on anything too good.

[Paul Roark]

At one point I tried some of the Krylon and other alternatives.  This was some time ago, but what I found was that the nozzles of the cheaper alternatives did not allow me to get as even a coating.  It may be that some are better than others and that spraying technique and learning could offset the nozzle differences.

Paul
www.PaulRoark.com

[Frodo]

Thanks Paul, Ernst and Dan for your replies and helpful suggestions.

What I thought might be a simple question of which aerosol spray then evolved into solvents or water-based, then roll or spray.
I've come to the conclusion (as suggested by Paul) that I need an aqueous coating for my Epson cold press natural paper mounted without glass.  I will try BC Glamour II matt as it dries slower and dilution makes it more cost-effective than Timeless.  Will try how mounting prints with Glamour works (I currently use Scotch 568 repositionable adhesive).
I will see how rolling works as this is less hassle than spraying and I'm hoping irregularities will not be as obvious on a matt print. 
My outstanding questions are how much of a glass/satin it imparts on the print and if/how much Dmax I lose.  I guess I will find out!

Thanks, Bob

[Paul Roark]

Bob,

I'm not sure what size prints you make, but in my experimenting with coating, I found that a "Mayer" or "wire wound" rod could do a very good job up to about 11x14 inch size with the water based coatings -- better, in my view, than a roller.   Beyond 11x14 I was not able to scale up the process.  Since my target prints were larger, I stopped pursuing that approach.  If you're interested I can dig up my old notes on this.

Paul
www.PaulRoark.com

[robertDthomas]

I would be interested in your notes on the Mayer approach.  Not wanting to hijack the discussion but looking at using that for coating of plastic and thin metal sheets with an inkjet receptor coating and can't find much info on the approach for using and locating the rods.

[bteifeld]

For mayer bars:

www.rdspecialties.com

Video from RD Specialties demonstrating use of a mayer bar:

https://www.youtube.com/watch?v=Y-iDF1pKJJA

Mayer bar rod size chart from RD Specialties:

https://www.rdspecialties.com/pages/size-selection

[Paul Roark]

The rods I have came from Diversified Enterprises, Claremont, NH.  The one that is use regularly these days if for ink, however, not coating.  The viscosity is way different, so the size would not be the right one.  It looks like Diversified is still there, but the internet takes me to https://www.accudynetest.com/laboratory_metering_rods.html when I look for them.  So far I have not found notes on the size I found worked best for the polyurethane coating I was using.  Some of the coating suppliers may have ideas as to size.

I found that glass on a towel on a flat surface resulted in the flatest surface for the pull-down.  Thicker glass is needed for larger prints.

I did not use their pre-made base.  Rather, I found taping the paper to the glass, and then running a bead of the coating along the tape worked for smaller prints.  Having enough coating to not have the draw-down go dry before the end of the print is something you'll have to experiment with.

An even pull with even pressure is key to an even coating.  That is probably the reason for their pre-made bed.  However, I think their size limitation is what stopped me from going with it.

With the water based coatings, be aware that they don't dry totally for a long time.  Stacks of prints that you thought were dry will stick together.

There are obviously a number of issues with these coatings and using a rod for application.

If I find my notes, I'll add to this.

Good luck.

Paul
www.PaulRoark.com

[alain]

...
 Despite the odor (white spirit dissolved acrylic) the Talens 680 protective varnish is quite good. With all be aware that higher temperatures can harden the varnish faster and give an uneven image surface quality.

Met vriendelijke groet, Ernst

http://www.pigment-print.com/spectralplots/spectrumviz_1.htm
March 2017 update, 750+ inkjet media white spectral plots

My experience with the Talens 680 is to avoid temperatures below 15°C.  If unavoidable I bring the can to "room temperature" (20°C) before spraying.
I'm very happy with the Talens 680, but I follow Ernst about the odor ;-)

Alain

[patjoja]

I use Hahnemuhle Protective Spray for all my framed photos (framed without glass).  It's actually a lacquer based spray which is extremely quick drying.  It provides UV  protection and some abrasion and fingerprint resistance.  It does have a rather strong odor when sprayed so I installed a spray booth in the workshop to allow me to spray any time of the year.

Patrick

[Frodo]

I found it difficult to get the Print Shield spray here so I tried two readily available and cheaper sprays that are marketed as for photographs: National Art Materials Crystal Clear and National Art Materials Matt Spray.  Both are made in Australia.  I recognise the benefits of non-aerosol coatings, such as Breathing Colour Timeless, but for the moment an aerosol spray has benefits in convenience.

I printed off a 255 step black to white image on my P600 onto Epson Cold Press Natural, which is my main b/w paper.  I then covered strips of the print and applied both sprays.  The results are quite staggering.  The Matt Spray kills Dmax to the extent that it has very limited use.  The Crystal Clear, on the other hand, actually increased Dmax.  While it is marketed as a gloss spray, there was no visible increase in gloss at all. 

In the image below, the strips are: no spray; (m) Matt Spray, (g) gloss (Crystal Clear), no spray, (m) Matt Spray, (g) Crystal clear, no spray.

There was no visible colour cast (the bottom right appears slightly warmer, but I think this part of the paper was curled up shielding the cooler sky light).

I'll use the Crystal Clear spray in the future.  Any info on its longevity would be appreciated.

Bob

[mearussi]

I found it difficult to get the Print Shield spray here so I tried two readily available and cheaper sprays that are marketed as for photographs: National Art Materials Crystal Clear and National Art Materials Matt Spray.  Both are made in Australia.  I recognise the benefits of non-aerosol coatings, such as Breathing Colour Timeless, but for the moment an aerosol spray has benefits in convenience.

I printed off a 255 step black to white image on my P600 onto Epson Cold Press Natural, which is my main b/w paper.  I then covered strips of the print and applied both sprays.  The results are quite staggering.  The Matt Spray kills Dmax to the extent that it has very limited use.  The Crystal Clear, on the other hand, actually increased Dmax.  While it is marketed as a gloss spray, there was no visible increase in gloss at all. 

In the image below, the strips are: no spray; (m) Matt Spray, (g) gloss (Crystal Clear), no spray, (m) Matt Spray, (g) Crystal clear, no spray.

There was no visible colour cast (the bottom right appears slightly warmer, but I think this part of the paper was curled up shielding the cooler sky light).

I'll use the Crystal Clear spray in the future.  Any info on its longevity would be appreciated.

Bob

The only longevity tests I've seen for any coating has been for Premier Art's Print Shield (approximately a 25% increase) and their Eco Print Shield (>2x increase).  Both tests are from Henry Wilhelm.

[Dan Wells]

I wonder if Canon's (and HP's) clear coat inks have positive longevity effects if applied in "overall" mode? They seem to have a similar effect on gloss differential to spray coats - I have no idea if they are chemically related. If so, they're an interesting question cost wise - they are much more expensive per ml, but also much more efficiently applied.

Dan

[Ryan Mack]

I’d think we could figure out if there should be an effect (but not the amount) by measuring whether it blocks UV trying to hit optical brighteners.

[Ernst Dinkla]

The only longevity tests I've seen for any coating has been for Premier Art's Print Shield (approximately a 25% increase) and their Eco Print Shield (>2x increase).  Both tests are from Henry Wilhelm.

Aardenburg-Imaging had some tests with and without protection varnishes.


Met vriendelijke groet, Ernst

http://www.pigment-print.com/spectralplots/spectrumviz_1.htm
March 2017 update, 750+ inkjet media white spectral plots