RE: Digital Negs - RGB vs CMYK

From: Don Bryant ^lt;[email protected]>
Date: 12/01/04-11:40:33 PM Z
Message-id: <>


> Let me suggest that that depends on your printer.

And your inkset and kind of ink. As I remember you are using the inexpensive
non OEM inks and they are dye based not pigments. Additionally the media
setting in the Print Quality setting found in the Epson Driver dialog box
will affect the opacity too, not to mention the printer DPI setting. Of
course since you are using OS something or another with your G4 (or is now a
G5) the exact settings may be described differently.

> In my experience with
> the Epson 1160, printing negatives in "color," which had a kind of bluish
> cast, gave significantly less density (or maybe that's opacity) than just
> black. Also, and even more important, each printer has its own notions of
> what colors to use to make "black" --

If you choose black only in the printer driver then only black ink will be
used. Also it is usually best to turn off any color management in the driver
and have the color management set to Same As Source.

> > This past week, I sat down and experimented to see whether this is true
> of my Epson. It
> > certainly was. My "all inks" neg - b&w - is vastly superior to the
> "black only" version. It's
> > so bad that it's evident to the naked eye.

What is evident to the naked eye doesn't always translate to what is best
for UV printing. Sandy King's posts repeating the point that the UV density
of a negative is quite a different one than the visual density has convinced
me of that along with my own experience, especially with the Durachrome
printers such as the C80 or C84 and the Epson 1280.

> As noted... not necessarily. Plus, I found that the substrate is another
> variable. If that changes, density may/will change

Ditto on that!

> On the 3rd hand, this is all probably overkill -- does anyone print gum
> for exact "photographic" color repro?

No, but ink color can be optimized for any process for a specific contrast

> Not to mention that the process
> itself is so extraordinarily, infinitely flexible -- in coats, mixes,
> choice of colors, development, repeats, additions, etc. etc. -- that the
> negative is in a sense academic -- in the sense of being theoretical
> rather than definitive.

I would think that because of the variability of gum printing one would
strive to eliminate the variable of the ink jet negative even for creative
reasons, otherwise you end up shooting in the dark, especially for beginning
gum printers like myself. However I am not suggesting that gum is an exact
science nor should it be but having one less thing to worry with is a

> And, for what it's worth I'll add that I printed my negatives by CMYK in
> black, because (a) at the time I didn't know there were alternatives & my
> laser printer didn't speak RGB, and (b), I was familiar with CMYK from dye
> transfer, but that (c), the prints were, if anything, TOO realistically
> "photographic," which was one reason I lost interest in that particular
> project.

Using all black ink probably is the most straight forward method. I also
believe that each color layer could potentially be printed differently. To
figure this out would probably drive one nuts but the question does arise,
how to create and apply the required adjustment curve or curves. Apply a
curve to the image before separation or separate and apply curves

Don Bryant
Received on Wed Dec 1 23:40:42 2004

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