Digital BW, The Print

Following on my Lab readings post of a grayscale printed with the 
AdvancedB&W settings of the R2400, I have just repeated what I did with the 
R1800 - printed to file 28 gray patches ranging from 
0,5,10,20,30,.......................240,250,255.

The 'prints' were on Epson Premium Glossy, with PhotoRPM, and the default 
settings for AdvancedB&W (neutral/darker) on the R2400.

Looking at the printer files (with help from Roy Harrington) it seems that 
the three blacks are the main inks used throughout the scale.  The PK ink is 
used from 0-90, the lk ink from 0-170, and the llk ink from 20-250. No inks 
are used at 255 unless you check the Highlight Point Shift box, as I 
explained in an earlier post.

The neutral toning is done with light magenta and light cyan througout the 
whole range 0-250, and yellow is also used from 5-250. Amounts of toning are 
variable, but at 210 for example (where only the smallest dots are used for 
each ink) 72% of the ink was llk, 16% lm, 10% lc, and 1% Y. At 250, the llk 
was 82%, with 9% lm, 7.5% lc, and 1.5% Y.

Further down the scale, I can't directly compare the % of the different inks 
because the blacks, and occasionally the lm, use medium drops as well as 
fine, and I don't know the exact size ration of the three sizes of drops 
(does anyone else?), whereas the others usually use just fine drops.

So the use of the Y ink, which seems to worry some people, is in very small 
amounts, and we don't know whether this Y ink is better than the old ones or 
not as regards color shifts.

Hope the info is useful.

Bob Frost.