Digital BW, The Print

John,

I've just got round to measuring the tests that compare simultaneous
coating using IJC/OPM and coating in a second pass, using the Epson
driver, about ten minutes after the original prints were made.

The original IJC profile for this test uses the PK, LK and LLK inks
from the K3 set in an Epson 2200.
Epson Premium Glossy Photo paper.

IJC settings for 822 channel: limit 26 (ie max) 0, 250; 255, 250 (ie a
straight horizontal line from zero to 255 at just below maximum ink level.

Epson driver settings: Watercolor Radiant White (there is an MK cart
in the first slot, the PK is in the second slot so the Epson driver
thinks it is loaded with MK), 720 dpi, High Speed

The IJC simultaneous coat appeared to be thinner than the Epson
second-pass coat, and it still showed some slight gloss differential.
The second-pass coat had none. The simultaneous coat actually lowered
the D-Max by about 0.1 and the density at the greyscale value of
around 5 (on 0 - 255) was lowered by around 0.2 - thus increasing the
shadow separation. The second-pass coat raised the D-Max by about 0.1,
with the increase rapidly tailing off by about 5, which also increased
the shadow separation. I have the impression that the second-pass coat
allows more black ink to be put down, but that's just an impression -
I have, as yet, no real evidence. When I have time, I'm going to tweak
the profile in an attempt to make the most of the 822.

Best,
Helen

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "John Moody"
<moodymz3@y...> wrote:
>
> Helen,
> OK, it is starting to make sense now, thanks.
> The 822/824 thing sounds just like the MIS �what new base?� response.
> Have you tried creating an IJC 822 channel in your printing curves,
or do
> you prefer to put down a uniform coating after printing?
> 
> Best regards,
> John Moody