Re: RGB vs CMYK: gamut and some important notes for CMYK users

From: Joe Smigiel ^lt;[email protected]>
Date: 12/05/04-09:56:53 AM Z
Message-id: <>


I look forward to seeing your examples and would welcome any other
visuals on this topic.

I have some free time coming up over the semester holiday break and so
I'll go out on a limb here and state that I'll attempt to define a
better gum correction curve, Photoshop CMYK space, and soft-proofing
method for the particular materials I use in gum printing. I don't know
if I can do that properly, but I did take a workshop on color management
a few years ago so perhaps this will provide an opportunity to actually
use that theoretical information on something practical. I'll share the
results with the group regardless of the outcome. Whether others may
find it useful is anyone's guess.


>>> 12/05/04 9:46 AM >>>
Good morning all,
After being in the darkroom til 1:00 AM last night getting some bromoils

ready, I appreciate coming back to this thread because in my dark time,
got to a thinkin'.

Question: is it easier/more accurate/more realistic to use RGB vs.
Or does it boil down to matter of preference, a matter of working with
you're used to--you grew up drinking whole milk and skim tastes like

On the RGB side IN PRACTICE: Sam, myself, Katharine, perhaps Judy?
(add names here)

On the CMY side IN PRACTICE: Keith (maybe both sides), Joe,
names here)

Shortly I will have about 20 of my gums online, so I can show the RGB
ones I
have been doing. I mean, I didn't think there would be a better way to
with the gum process because we are dealing with subtractive color here
(pigment on paper). But I am very willing to be enlightened.

I think Joe is right; those of us using one method should try the other.
my next gum I do, I will print side by side, same method of pigment and
development and all else, RGB and CMY for an example. Then, if the CMY
looks weird, I will see what I might have to do to add to it in any way.

Maybe it'll be perfect and I will have "seen the light".

The only problem: I don't know what SWOP is, and I have no idea of the
steps to go thru in Photoshop 7 to get the negs to where you want them
to be
in CMY. Could someone please please write a SIMPLE 1,2,3 list for me so
can do it right? No heavy computer terminology. It would be helpful to
those LURKING gum printers out there, too, who are afraid to post
Like, do I absorb the K channel into the rest?

Forgive me if this has already been done; I have read every one of the
carefully, but perhaps need it said more simply. But I'm up for a
challenge--yeah!! Actually, I am really willing to see if there might
be a
better way than RGB, knowing that my test will certainly not prove
in the gum process (unless every one of us does it and comes up with the

same result--any more takers?)

What most interests me is in **teaching** neophyte gummists, whether one

system would be better than the other, as Joe has attested the CMYK is.
Received on Sun Dec 5 09:55:19 2004

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