Digital BW, The Print

The 3880 is filled with Eb6 in the "standard" color positions: Y = Eb6Y (2%), etc. See http://www.paulroark.com/BW-Info/Eboni-6.pdf at page 3. I'm using my C6b base for this. The profiles are all the same for MIS-diluted or generic base dilutions. The C6b version uses only readily available inputs and works fine. (See http://www.paulroark.com/BW-Info/Ink-Mixing.pdf page 5)

Where I varied the setup a bit is with the LK and LLK. Originally I recommended LK = Eb6-M = 18% MK, and LLK = Eb6-LM = 6% K. I've found that I prefer using the Eb6-C (30%) and LC (9%) for these positions. I think they make for a better gray ramp with the Epson driver, and I really like having, particularly, the 30% LK as a manually-drawn QTR curve. It's relatively cool and dense enough to perfect the glitches in the gray ramp all through the scale. As nice as automated linearization is, the better the pre-linearization curve, the better the final is likely to be. A single manual curve that can act as, among other things, a manual correction curve is handy.

With QTR, as a starting profile, I have a main partition of the color inks as usual -- a standard QTR semi-automatic partitioning. Then I have the LK and LLK in a "toner" partition. This too can simply use the density numbers for those inks as determined in the usual way. QTR will do a fine job of partitioning the "toner" channel. I split the ink loads 70% to the main partition and 30% to the "toner." (QTR does not lower the gray partition ink loads to compensate for the fact that there is also a toner channel.) The resulting pre-linearization curve will be very good, meaning that it will linearize very well. This is all standard, semi-automaic QTR profiling - nothing fancy at all, and it works very well.

This approach is just for the simple, default, relatively warmer profile. The real challenge is to get a relatively neutral print out of 100% carbon. For that the LK (30%) is used like I use the 100% MK in a 1.5 picoliter printer, like the 1400 family. I can't use a black only channel in a 3.5 pl printer and have what I consider acceptable smoothness. But, I can have a "toner" of LK (30%) that has somewhat the same effect. The 30% K blend is not as neutral as the 100% MK but it's considerably more neutral than the more dilute inks. I've found with the 7800 that I can pull the delta Lab B (paper white to maximum Lab B) down to 3 with this approach and have a print that viewers consider very smooth. For more neutral than that, it's color toner time, and that will be the second inkset I set up on the 3880. However, there was enough demand for a full-on 100% carbon approach with no color pigments at all that I thought I ought to do that first. It is the simplest and most archival, not to mention least expensive, approach.

(I need to know there are reliable carts, however, before I put a lot more effort into this machine.)

Paul

www.PaulRoark.com