How many inks would make a difference?

[Dan Wells]

There seems to be a standard set of 8 inks (9 including photo and matte black) that everybody uses (CcMmY plus black and 2 grays). Epson generally puts that in 8 channels by switching PK and MK,while Canon and HP use 9 channels to avoid the black switch.

At 10-12 channels, approaches differ a bit.

Epson most commonly adds orange and green to their 8 ink system, to get 10. Variants include losing a gray and substituting violet, and also starting with 8 (forgoing orange and green), but ADDING a gray and eliminating the PK/MK switch. I am not aware of any Epson printer with more than 10 channels, although there may be one.

Canon and HP start with 9 channels (no PK/MK switch)  and add different things to reach 12. Canon's longtime approach has been to add red, green and blue, and HP loses cyan (while retaining light cyan) to add red, green, blue and a gloss optimizer. Recent Canons sacrifice green for a gloss optimizer, and, in a few desktop printers, also sacrifice blue for an extra gray (still 12 channels in both cases).

Assuming that Epson's violet is a relative of what Canon and HP call blue, and that Epson's orange is related to the Canon/HP version of red, we have a total of 14 possible channels used in current printers
3 bluish colors:Cyan/Light Cyan/Blue or Violet
3 red/magenta colors: Magenta/Light Magenta/Red or Orange
5 Neutrals (some third party ink sets use even more, but I've never seen a printer manufacturer use more than 5): PK/MK/light gray/gray/dark gray
1 Yellow
1 Green
1 Gloss Optimizer

Will anyone make a 14-color printer? If someone were to make a 15 or 16 color printer, what would the extras be? An extra dilution of yellow or green? 6 or 7 neutrals (there is a Cone ink set with 7, I believe)? Metallic colors aimed at the graphic arts market?

At least a 14-color printer seems to offer real advantages... Start with Epson's 10 color inkset , which has the best gamut around except in the deep blue/violet (where Canon's and Hp's blue inks have real advantages), then add a dark blue ink, an extra gray, a gloss optimizer and eliminate the PK/MK switch - that's 14 colors, and Epson has actually used them all (except the gloss optimizer), just not in the same printer.

Going all the way to 16 channels, at least one of the extras would be a gray (for photographers -  the graphic arts market might prefer to use them on metallics, or a white ink to print on black media) - is the other a seventh gray, or light yellow-green?

[shadowblade]

This is what I would like in a 16-colour printer.

8 black/grey channels (similar to Piezography Carbon with both PK and MK)
C/lc
M/lm
Y
Red
Green
Brown

For black-and-white, you'd have the full Piezography Carbon setup for quality and longevity, with colour inks for toning if needed.

For colour, you'd have the baseline CMY plus light inks. But CMYK tends to be especially weak in the reds and greens - vivid colours found commonly in nature, so I'd strengthen these areas with dedicated red and green inks (IMO blue ink doesn't add much over cyan and magenta, so I'd skip that). I'd also add a brown ink, since getting a bright brown - another very common colour in nature - without making it appear muddy can be difficult, especially on matte media.

16-head printers are not unprecedented - Roland and others manufacture them. Just that they're usually used to run CMYKx4 for speed, rather than adding extra inks for quality.

[Ernst Dinkla]

There has been a desktop inkjet printer with an extra light yellow. I doubt it is needed with today's droplet sizes.

On the absence of the Cyan in HP Z models that rely on Light Cyan + Green + Blue (violet) to fill in that gap; I never noticed a weakness in the blue green hues of my prints. Suppose the Z's were used just for matte prints I would substitute an extra grey for that gloss enhancer channel. The quad grey ink mode on matte papers uses the PK as the darkest grey before MK kicks in. That PK ink is quite dense itself so does not add much to the concept of Quad inks.

16 channels on a printer may add more than the 33% nozzle issues that the 16/12 ratio suggests, the extra hue ink carts usually empty with snail's pace and it will not get any better with 4 inks on top of that. Ink technology on gamut+longevity improved in the last decades so I would bet on that.

Met vriendelijke groet, Ernst

http://www.pigment-print.com/spectralplots/spectrumviz_1.htm
January 2016 update, 700+ inkjet media white spectral plots

[shadowblade]

As I mentioned elsewhere, I think this is an area ripe for capture by Chinese manufacturers. They currently make more inkjet printers than anyone else - aqueous, solvent or UV - and produce solid, noisy, reliable machines that require little maintenance. Certainly much less than the super-precise, but temperamental, Epsons. But all of them are geared for high-volume signage and automotive printing. Some have many heads, but run multiples of CMYK for speed. The software is rudimentary, and generally require some sort of RIP. They come in both roll-to-roll and flatbed models.

The thing is, these companies make printers, not ink - unlike Epson/Canon, they have no interest in making you buy OEM ink month after month. You can put anything you like into the ink tanks, and the printer will squirt it out. Tolerances are generally looser, too, making them both cheaper and more able to print a lot of different 'inks' (and I use the term loosely, since they can squirt just about anything onto a substrate).

All it would take is just one manufacturer to decide to cater to the photography/fine art market, producing a 12-16 ink, 44"-wide printer (instead of 2-5m-wide industrial behemoth) and it'd probably become the new Samyang/Rokinon, or even the Sigma, of the photo printer world. Just supply a printer with the requisite ink tanks and at least 1200dpi, along with some RIP software to control it. Then fill the tanks with whatever inks you want - a dedicated black-and-white set, extended-gamut colour pigments, long-life inorganic pigments, even liver cells for tissue engineering - linearise the output and start printing with your own, custom inkset. Certainly not for everybody, but I think they'd find themselves a comfortable niche among those in-the-know and those producing high-end, custom prints.

[shadowblade]

There has been a desktop inkjet printer with an extra light yellow. I doubt it is needed with today's droplet sizes.

On the absence of the Cyan in HP Z models that rely on Light Cyan + Green + Blue (violet) to fill in that gap; I never noticed a weakness in the blue green hues of my prints. Suppose the Z's were used just for matte prints I would substitute an extra grey for that gloss enhancer channel. The quad grey ink mode on matte papers uses the PK as the darkest grey before MK kicks in. That PK ink is quite dense itself so does not add much to the concept of Quad inks.

Fortunately, super-saturated cyan isn't a colour that's commonly seen. Strong greens and blues, however, are. If you already have green, magenta and light cyan, you probably only need one of either cyan or blue.

16 channels on a printer may add more than the 33% nozzle issues that the 16/12 ratio suggests, the extra hue ink carts usually empty with snail's pace and it will not get any better with 4 inks on top of that. Ink technology on gamut+longevity improved in the last decades so I would bet on that.

That's true with typical profiles, which tend to maximise the use of CMYK and just use the extra colours to extend gamut where needed.

Not necessarily true with a custom profile via a RIP. For instance, running the Epson 7900 via a RIP, to minimise the use of the poor-longevity yellow ink, tends to greatly increase the use of orange and green inks. It also seems to increase the gamut.

With regards to nozzles, I prefer the Canon/HP version of having heaps of redundant nozzles to Epson's version of having a lower number of finely-engineered, expensive nozzles, with no redundancy. All it takes is a single clogged nozzle out of 10 heads to disable the printer.

[Ernst Dinkla]

That's true with typical profiles, which tend to maximise the use of CMYK and just use the extra colours to extend gamut where needed.

Not necessarily true with a custom profile via a RIP. For instance, running the Epson 7900 via a RIP, to minimise the use of the poor-longevity yellow ink, tends to greatly increase the use of orange and green inks. It also seems to increase the gamut.

The HP drivers  do a good job in substituting CMY mixes with the extra RGB inks at the right hue angles and saturation levels. BTW, the PS2 one is in many ways a RIP. In the opposite direction the HP drivers totally substitute composite CMY greys with grey inks at neutral. I have seen way worse Wasatch SoftRip results with N-Color profiles that showed RGB + CMYK inks droplets up to the neutral spine of the gamut shape. Sure it would empty the RGB carts faster but make ink use not more economically. Not to mention other effects like more "metamerism", less longevity and less consistency in color/B&W control. That said, the yellow of the Vivera pigment inkset was not problematic on longevity aspects so no need to substitute it. I wonder whether your Brown ink desire has anything to do with that Orange Green ink mixing approach :-)

Yes, a 16 channel Epson head with one nozzle failing permanently is like ending second in the general ranking of the Tour de France. Missing one in a 10 channel head falls in the Vuelta category, less a PIT*.


Met vriendelijke groet, Ernst

http://www.pigment-print.com/spectralplots/spectrumviz_1.htm
January 2016 update, 700+ inkjet media white spectral plots

[shadowblade]

The HP drivers  do a good job in substituting CMY mixes with the extra RGB inks at the right hue angles and saturation levels. BTW, the PS2 one is in many ways a RIP. In the opposite direction the HP drivers totally substitute composite CMY greys with grey inks at neutral. I have seen way worse Wasatch SoftRip results with N-Color profiles that showed RGB + CMYK inks droplets up to the neutral spine of the gamut shape. Sure it would empty the RGB carts faster but make ink use not more economically. Not to mention other effects like more "metamerism", less longevity and less consistency in color/B&W control. That said, the yellow of the Vivera pigment inkset was not problematic on longevity aspects so no need to substitute it.

You certainly wouldn't alter the curves merely to even out the ink use. It's hardly an issue if one ink is used a lot more than others, anyway. Gloss optimiser comes to mind.

The HP drivers are nothing short of brilliant. Minimal ink usage, yet it delivers output comparable to the ink-hogging Epsons.

But extra colours help a lot to punch up the weak areas of the standard CMYK. Reds and greens especially - they're common in nature, and are weak because they fall between M-Y and Y-C respectively on the colour wheel. Bluish-violet is probably next, but is not commonly found in bright, saturated hues.

I wonder whether your Brown ink desire has anything to do with that Orange Green ink mixing approach :-)

Nope - just that, when you print an image with lots of different shades of brown, they can often appear muddy. Probably because multiple inks and a high ink load are needed to produce a saturated brown. I've seen output from a Roland printer running a custom inkset including brown - the difference in brown rocks and trees was subtle from a distance, but nonetheless significant - up close, the detail in the print was much better when put next to the same image printed on an Epson 9900.

Yes, a 16 channel Epson head with one nozzle failing permanently is like ending second in the general ranking of the Tour de France. Missing one in a 10 channel head falls in the Vuelta category, less a PIT*.


Met vriendelijke groet, Ernst

http://www.pigment-print.com/spectralplots/spectrumviz_1.htm
January 2016 update, 700+ inkjet media white spectral plots

Then build the printer around el cheapo, multiply-redundant, user-replaceable HP-style thermal heads, instead of complicated and non-redundant Epson-style piezo heads.

Better to have redundancy and easy/cheap maintenance than sophisticated perfection that falls apart as soon as one element fails. Look at it like an old-style, noisy engine with loose tolerances that can just keep on working and be repaired by any competent mechanic, versus a new, all-in-one, high-performance engine which needs an expensive overhaul or complete replacement once one part fails. Lots of examples in engineering history of the value of redundancy and idiot-proof maintenance...

[Dan Wells]

I definitely see Canon blues in water (the Canons with their dedicated blue ink do deep water significantly better than Epsons), and Epson greens and oranges in forests (Canon's green is weaker than Epson's). An Epson-type ink set plus a blue (or Canon with a better green and orange, assuming that Canon doesn't simply have a weaker per-ink gamut - does anyone know how an 8 ink Canon compares to an 8 ink Epson, to judge the core inksets before adding the extra colors?) would definitely be better than either alone... There have been several requests for a brown ink - has one ever been used in an inkjet? It would have some real advantages in toning B+W , in addition to its color gamut...

[shadowblade]

I definitely see Canon blues in water (the Canons with their dedicated blue ink do deep water significantly better than Epsons), and Epson greens and oranges in forests (Canon's green is weaker than Epson's). An Epson-type ink set plus a blue (or Canon with a better green and orange, assuming that Canon doesn't simply have a weaker per-ink gamut - does anyone know how an 8 ink Canon compares to an 8 ink Epson, to judge the core inksets before adding the extra colors?) would definitely be better than either alone...

I'd start with the HP inkset and expand from there, to end up with an inkset that's both extremely long-lived and has a large gamut.

HP inks use bigger pigment particles than either Epson or Canon, which likely explains their inks great longevity and their deeper blacks on matte paper. It also explains their slightly weaker gamut, except in parts of the gamut where HP has an ink and Epson/Canon don't. This can be compensated for by increasing the pigment load. With the decade that's passed since the release of the Vivera inkset, there have been lots of developments in pigment encapsulation and dispersants which allow for increased pigment load without increased drying and clogging, which is probably why the new Epson and Canon inks have managed a greater pigment load and gamut than the Lucia EX and Ultrachrome HDR inks they replaced. The same could be done with a new generation of Vivera inks; replace the blacks with carbon and add in a few extra shades and you'd end up with an excellent solution for both black-and-white and colour printing.

There have been several requests for a brown ink - has one ever been used in an inkjet? It would have some real advantages in toning B+W , in addition to its color gamut...

There are some custom Roland printers around using brown inks (developed by American Inkjet Systems). The results are fantastic. The company is unreliable, unfortunately.

Yes, brown and blue-violet would be fantastic choices for toning black-and-white carbon prints. It also helps that there are options for each (inorganic pigments) which are basically as lightfast and unreactive as pure carbon pigments. After all, ochre cave paintings have been with us for millennia.