[Chimera-users] RGB->CMYK color conversion
gregc at cgl.ucsf.edu
Wed Nov 2 16:23:29 PST 2005
More information in a FAQ-style:
Which CMYK profile should you use?
If you know the printer, use its profile. The original question was about
a Textronix Phaser 740. Tektronix paid to have that printer calibrated
and the profile is available from
<http://www.pantone.com/support/support.asp?idArticle=72&>. It is also
available from the manufacturer (xerox.com since Xerox bought Tektronix's
printer business a while ago).
What if a journal requires CMYK and they don't provide a profile?
If you want the colors printed in the journal to match what you submitted,
you'll need to ask the publisher for a profile. If you're too shy, you
can guess. For instance, many of the Elsevier publishing group's journals
still require CMYK but the author instructions don't say which CMYK
profile to use. Since they are European company and print on glossy
paper, I'd recommend the "Europe ISO Coated FOGRA27" color profile from
Where can I get Adobe ICC color profiles?
Adobe provides free ICC color profiles on their download page,
<http://www.adobe.com/support/downloads/>. In that set of ICC color
profiles there are 10 different CMYK profiles designed for different kinds
of paper and standards (US, European, Japan). Those profiles are also
provided in PhotoShop and some other Adobe products.
When else would I want to use color profiles?
If you're going to send your images to an online photo service, say for
printing a holiday greeting card with a chimera image on it, then you'll
want to use the printer profile provided by that service. For example,
Costco.com provides printer profiles (the profile can make a huge
difference, especially with wedding pictures).
I'm using a printer color profile but the image changes color?
The printer profile is used in conjuction with your monitor's profile to
preview what will be printed. That set of colors is the common subset of
the colors that the printer and the monitor can reproduce. It is the
previewed colors that will match what is printed, not the original colors.
The colors should be very close to the original colors, but slightly
How do I get my monitor's color profile?
Any recent monitor should come with a color profile. Alternatively, you
could use the standard sRGB color profile as an approximation. You also
should calibrate your monitor to produce a full range of brightness (if
there is too much light shining on your monitor, this is impossible).
See <http://www.pawprint.net/designresources/monitorcalibration.php> for
one possible method. If you google for "monitor calibration" you'll find
more than you care for. Ideal monitor calibration uses a colorimeter to
measure the color on the screen (but it's impossible to be perfect, e.g.,
LCD monitors are brighter in the middle than on the sides).
More information about the Chimera-users