A different all-black ink printing method

[costadinos]

Just came up with a different approach to printing black and white using only black inks, and I thought I should share it for those interested.

Instead of using custom profiles, RIP software, or specialized all-black inksets (expensive), I simply used black ink in all the cartridges of a 1400, diluting it with different ratios with gloss optimizer for each of the six colors, and then printing normally in color using the profiles I created for the colour inkset.
I used undiluted OCP pigment black for the black channel, 60% dilution for the Cyan, 40% for the magenta, 10% for the yellow, and 2+1 parts dilution of the Cyan and Magenta for their Light counterparts.

In all honesty, I wasn't expecting the results to be that good on the first try, but here's a scan of two prints that clearly shows how well the method worked:

On the left are the prints from the all-black 1400, and on the right from an R2000, using the normal driver, and with custom profiles created with an i1 Pro (it appears there were a couple of clogged nozzles on both printers, ignore that). The top two were printed as colour (for the R2000 I simply desaturated before printing) and the bottom two were both black and white to begin with, but also printed as colour images.
Apart from that green cast that plagues the R2000 print, I can't really see any other differences, and what's more, gloss differential was completely gone (the extra GO sure had something to do with that), the print was absolutely neutral, and the tonal range didn't seem to be affected. Overall the print looked punchier.


I came up with the dilution ratios by visually examining the original inks (very rough method) and diluting black ink until the opacity looked the same. And this is where someone with maybe an optical densitometer or more willing to experiment can help improve this further; if we manage to determine the exact dilution ratio that would result in ink having the same density (or opacity in that manner) with a colour ink, then using that diluted ink and printing in colour using the profiles created for the particular inkset should result in pretty good black and white prints.

 

[jtoolman]

I love that idea and I DO have an extra 1400 to play with and plenty of OCP Blacks and GO.
I have two 1400s, one is now running on only GO for over coating pigment prints suffering form Gloss and Bronzing problems.
The second is running color inks which is really redundant since I have a PRO9000MKII and PRO-100 currently in service.

I wonder how this would print using the QuadtoneRIP. Assuming the dilutions of the black could be adjusted to match those of the very expensive Piezo Black inks form CONE.

Sounds like another FUN experiment!

Joe

 

[thanhhuy123]

Can you tell us in details how to dilute ink? What do we need to dilute ink? Can the ratio be used with any ink branch?

 

[costadinos]

I wonder how this would print using the QuadtoneRIP. Assuming the dilutions of the black could be adjusted to match those of the very expensive Piezo Black inks form CONE.

That's an interesting question, and matching black to black shouldn't be as hard as matching to a coloured ink. Maybe someone using the piezo set can give it a try. An easy way doing that would be by placing the two bottles side by side and a flashlight on the back, and, starting with some quantity of clear GO in the second bottle, keep pouring black ink until their densities match...

Can you tell us in details how to dilute ink? What do we need to dilute ink? Can the ratio be used with any ink branch?

There's really not much to it, I simply used the clear gloss optimizer (it's used in the R2000 and R1900) and diluted to the ratios I mentioned (for instance, for the Cyan, 6 parts black and 4 parts GLOP). I guess you could also use distilled water if you are certain the inks you are using are water based.

 

[jtoolman]

When I worked in a bio research lab we did many a test which involved measuring the optical density ( OD ) of a fluid using a spectrophotometer. You filled a Quartz cuvette of specific dimensions with the fluid. The instrument would shine a beam through the fluid filled cuvette and give you the optical density of the fluid. Distilled water being used as the calibrating baseline.

This would be the perfect way to prepare the dilutions. Tested against matching actual samples of the Piezo inks.

Too bad I no longer have access to these great toys.

So it would have to be the flashlight behind the bottle way for me.

I do have about 20 ml each of the all Black inks from Inksupply that aren't really dilutions but instead a combination or cold, warm and neutral black with two shades of the neutral plus GLOP. Total 6 "INKS"
This is used in the 1400 loaded in specific original color locations.

The regular driver is used to print and the results were very good.

But if one can do as you have done with the super cheap OCP black inks and get great results then that would be quite a breakthrough.

Joe

 

[costadinos]

I do have about 20 ml each of the all Black inks from Inksupply that aren't really dilutions but instead a combination or cold, warm and neutral black with two shades of the neutral plus GLOP. Total 6 "INKS"
This is used in the 1400 loaded in specific original color locations.

Joe

I haven't had any experience with that inkset, but if I understand it correctly, there are only three shades of neutral grey plus the GO and two shades for toning, therefore when printing a neutral image, only three inks will be used, right? So there's no advantage over using the three shades of grey of K3 inkset.
If you use the combination I used above, you get six different "shades" of grey instead...

The more I think about it though, the more I realize that we just need to obtain the relative opacity of any inkset for which color profiles exist (maybe from the technical data provided by some manufacturers?), and then we would be able to print using that specific icc profile.
Or, if we were somehow able to force the printer to print using only a single channel, we could print blocks consisting of the 5 colours and take some readings with a spectro.

If we got the dilution ratios right we should, in theory, be able to reproduce any image in black and white, with the accuracy of the original colour profile (regarding tonal range).

 

[mikling]

I still don't get why someone would want to use this method over a newer true K3 dye or pigment printer. Here's why. In outputting B&W, the same inks are used when using 3Ks. Now here is where the K3 solution comes into play. The K3 printer will tint for you using LC and LM etc. That way a good profile will be neutral and have only two possible areas of non linearity. In using 6 Ks I see 5 possible points of non linearity and crossover issues. Now if the K3 printer was not able to produce as fine a grain, and the 6 color machine, then yes. Finally, with the profile, I can use something like , PS and Silver Efex etc.and get predictable results with any kind of toning I wanted. That would not be possible with gray inks only.

So maybe I'm missing something here. It's a lot of work to get the QTR setup and play with the linearity and get that circle perfect. I could see doing this in the days when droplet sizes were large and 3K printing was not around. However, with today's printers is this idea past its time unless you did not own a 3K printer? The only other area I could see this is for true Carbon printing where no other colors are allowed and one accepts the warm tones produced...which is exactly what is done. Dilution of a true Carbon Matte Black (1082) into grays for the other color channels.

 

[jtoolman]

Except there are tons of people who are not at all interested in toned B&W prints.
My Black ink set from Inksupply did have those two toned inks ( Warm and Cool ) which in combination with the black gray and light gray did allow you to tone your B&W. It also used GO as the 6th "COLOR".
You could easily replace the two "Toned" blacks with neutral blacks of the same density.
You would loose the ability to tone, which would be of no consequence to me.

If I really want toned prints I can always use the R2400 / R2880 / PRO-3800 / Canon PRO-100 / PRO-9500MKII.

But there are folks who simply want to turn a spare 6 color printer into an all black one as they may not own a K3 printer.

Joe

 

[pharmacist]

Can somebody how I can achieve a similar result using PK, LB and LLB in my Epson WF-7525 ?

I was hoping to put PB in the Black cartridge and LLB in the Yellow cart, but what about the Cyan and Magenta carts ? Should I mix PK and LB in the Cyan and LB and LLB in the magenta ? What are the suggested ratio's ?

 

[costadinos]

Can somebody how I can achieve a similar result using PK, LB and LLB in my Epson WF-7525 ?

I was hoping to put PB in the Black cartridge and LLB in the Yellow cart, but what about the Cyan and Magenta carts ? Should I mix PK and LB in the Cyan and LB and LLB in the magenta ? What are the suggested ratio's ?

The idea was to simply replace the colored inks of an already profiled inkset with shades of grey of the same density.

I tried a different way of determining the ratios for the 1400 I used, you could do the same for the WF-7525:

1) print a few nozzle checks one on top of the other on photo paper, so you get some patches of pure color.
2) scan or take a picture of the paper and desaturate it in Photoshop (use the highest scanning resolution possible to be able to distinguish the printed pattern).
3) using a curves adjustment layer use the black eyedropper tool and click on a solid black area of the pattern of the black ink (that way the original black ink gets mapped to zero brightness value), and do the same with the white eyedropper using the paper white.
4) use the color picker to take "readings" of the rest of the colors. The brightness values (%) should give an indication of the dilution required.

For instance, I found the following for the 1400, and I have to say, it works like a charm, in fact, I never remember getting anything that good from any printer I had, including the 7900...

Yellow --> 60%, or 4 parts black/6 parts GO
Black --> Black
Light magenta --> 70%, or 3 parts black/7 parts GO
Magenta --> 40%, or 6 parts black/4 parts GO
Cyan -->30%, or 7 parts black/3 parts GO
Light cyan --> the same dilution as used in color printing, that is, 2 parts Cyan + 1 part GO

If you want to use the other two shades of grey you have, do the same as above to determine how much further you'd have to dilute them, or which colors can be substituted by each.