Re: Use of black ink on Epson Photo EX

[Dan Culbertson <danculb@concentric.net>]

In fact the Epson StylusRIP with CMYK profiles can do much *worse* than
just using RGB profiles -- there is a built-in function called "Press
Simulation" and with some versions of Adobe PS (on a Mac at least) it is
not possible to turn Press Simulation "off" (stays on "Default").  This
totally screws up any CMYK file you send through StylusRIP and messes up
any profile target (and thus the CMYK profile you make).  And, like CD
says, it has no black channel control so it just fools you into thinking
you are working in CMYK when you are really working in CMY only.

If you want to simulate working with StylusRIP (just to see what it does --
this isn't anything  you'd actually use for much - except maybe quadtones)
try this -- convert your RGB profile to a CMYK softproof profile with the
method on page 188 of Blatner and Frasers Real World Photoshop 5.  Use this
in profile to profile to convert an RGB file into CMYK (there will be a
blank K channel).  Make a real K channel with calculations or channel mixer
(again, this is just for fun now!).  Convert to Multichannel first, then to
RGB.  Then print to the RGB driver using "No Color Adjustment". The results
are the same as a profile to profile using the original RGB profile except
you now have a black spot channel that Photoshop blends into the RGB file
and which then is reseparated into a black channel by the RGB driver -- and
you did it the really long way around.

Sound like a screwey thing to do?  Well, so's StylusRIP!
But it is free with the Epson 3000 and worth every penny you pay for it.

Actually, if you just need something that reads Postscript and prints to an
Epson printer StylusRIP can be handy -- but it is just not a CMYK driver
and it is very very slow.

Dan Culbertson

>In a message dated 1/24/00 8:44:25 AM, jameswmc@frontiernet.net writes:
>
>>   Thanks for your help Gary. I'm using the Epson RIP on my EX
>>and will try various output using CMYK profiles and see what happens.
>
>CMYK profiles won't do much that RGB profiles won't with StylusRIP, since it
>lacks a black channel, and uses conversion similar to the Epsn RGB drivers.
>
>C. David Tobie





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