Red Component in Cool Inks


#1

I’m working on blending a cool and warm curve to create a neutral curve for Epson’s Legacy Fibre paper and I’ve noticed that the cool inks have a red component to their color based on my measurements (maxing out around a 1.5 value in the A channel) . There is no color in the CGO and I’ve run a number of prints so I don’t think it is remaining Piezo-flush. There is obviously also a blue component to the ink, but I cannot figure out how to remove this red component in the cool inks and therefore achieve a totally neutral print. I’ve noticed it with other papers as well and I’m wondering is it just that the cool inks can run slightly red?


#2

What is the B column numbers? Do you see these same A numbers on other gloss papers?

When making this cool ink we did add a small amount of magenta to counter-act the yellow/green of the small-particle carbon on gloss papers. Otherwise the cool curve goes completely cyan and there is no way to make a convincing neutral due to the warm-side mimicking a palladium print spectrum (aka, less rosy warm than our old-school carbon ink).


#3

Here are the numbers for 21 steps for the very light cool tone ink on legacy fibre, which is a matte paper with a confusing name.
L A B
97.66 0.19 0.68
96.02 0.34 0.59
94.54 0.48 0.51
92.86 0.62 0.44
91.28 0.74 0.34
89.64 0.84 0.27
88.13 0.95 0.22
86.51 1.04 0.16
84.98 1.15 0.10
83.55 1.23 0.05
82.22 1.30 -0.04
80.89 1.38 -0.15
79.63 1.45 -0.20
78.39 1.51 -0.22
77.25 1.54 -0.29
76.19 1.57 -0.35
75.04 1.60 -0.42
74.06 1.63 -0.46
73.16 1.64 -0.49
72.27 1.67 -0.55
71.25 1.68 -0.55

Some of this may be accounted for by the slightly warm shift that occurs because of environmental factors where I work. I haven’t yet put this paper through those stability tests yet so I’m not sure, but I still observe this in papers that have little to no shift such as hot press natural. HPN’s numbers for very light cool tone are:
L A B
96.68 -0.00 2.75
94.91 0.13 2.51
93.19 0.26 2.31
91.30 0.39 2.28
89.50 0.50 2.09
87.78 0.57 1.79
86.17 0.65 1.68
84.44 0.74 1.51
82.92 0.81 1.43
81.52 0.86 1.23
80.29 0.90 1.06
79.02 0.93 0.87
77.80 0.98 0.72
76.68 1.03 0.57
75.81 1.07 0.45
74.84 1.08 0.23
73.91 1.09 0.02
73.15 1.10 -0.24
72.47 1.11 -0.40
71.76 1.12 -0.51
70.88 1.15 -0.59

I do notice a small shift with dry down towards magenta in both warm and cool tones in light and very light values. It varies based on both paper type and environment, but I haven’t yet found a paper that doesn’t exhibit this.


#4

Just to add to this thread, I am getting a surprisingly warm curve on Canson Baryta even when printing with the included cool curve. It seems to be especially noticeable in the highlight and shadow portions. Any thoughts?


#5

Can you upload the curves you are using to print with?

best,
Walker


#6

Hey Walker - here are the curves and the 256 step measurements taken from them after a 48 hours dry down. 9900_CBP_Cool is just x900-Canson-BarytaPhoto-Cool run once through the linearization process.

9900_CBP_Cool.quad (8.4 KB)
x900-Canson-BarytaPhoto-Cool.quad (8.3 KB)
x900-Canson-BarytaPhoto-Cool.txt (7.5 KB)
9900_CBP_Cool.txt (7.5 KB)


#7

this is all way too warm. I’m measuring a B of -3 to -6 on our (weekly shake’d) carts on these papers . . . .

I’m going to give you a ring tomorrow to figure this out more in detail. Sorry for the delay on this, end of year stuff . . .

-Walker


#8

No worries. I appreciate it. Shoot me a message or email and we can work out a time tomorrow.

Thanks.


#9

Just for a bit more info - I just did an ink separation and measured it in spot mode with an i1Pro1 and i1 Profiler after a 30 second hair dry. Attached is a text file with the results.

Canson Baryta Ink Data.txt (3.8 KB)


#10

A little more info on this. Did an ink separation on Epson Legacy Fibre on my 9900 loaded with PiezoPro inks purchased at the end of 2016/beginning of 2017 and the same separation run on a p800 loaded with PiezoPro inks purchased in May of this year. I’m waiting for them to dry down to measure, but cool inks from this year are visibly much cooler, and don’t have that red shift I see in the older inks. The warm inks look about the same in each. Did the cool inks change formulation at all between end of '16/beginning of '17 and middle of '18? I also was getting a warm shift with the same original Pro inks in a 7900.


#11

We did not change the colorants or any other ingredients other than a slight shift in the steric stabilization of the encapsulated particles of pigment to allow for less settling action.

I think your larger printer settled due to lack of agitation of the ink carts and you printed out the cool colorant. Inks from 2018 onwards are more stable even when not shaking inks regularly although we always tell you to shake regularly, like once a week (as does Epson). Only Canon has agitators inside of their printers which do an agitation every 24hrs or so.

best,
-Walker


#12

I had agitated prior to printing the separations, but come to think of it the ink in the lines could have been not well agitated. If I agitate the carts, do an initial fill, and print another separation, I should see a difference if the agitation, or lack thereof, is the culprit, right?