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Author CMYK color accuracy
pmind

2007-06-20, 6:15 pm

Can someone please explain...I have just created a solid color
adjustment layer with the values of C=90, M=57, Y=0, K=0 (per customer
instruction), however when I double click on the adjustment layer I
see that the values have changed to C=91, M=61, Y=5, K=1. Every time I
change the values to use only 2 colors, they change back as described.
Must a certain number of the colors (say 3 or 4) contain a value in
order to use CMYK? Is it possible to use only 2 colors? Does this
situation have anything at all to do with the colors settings? I'm
using CS on a PC if that matters at all. Thanks in advance. Paul

Mike Russell

2007-06-20, 6:15 pm

pmind wrote:
> Can someone please explain...I have just created a solid color
> adjustment layer with the values of C=90, M=57, Y=0, K=0 (per customer
> instruction), however when I double click on the adjustment layer I
> see that the values have changed to C=91, M=61, Y=5, K=1. Every time I
> change the values to use only 2 colors, they change back as described.
> Must a certain number of the colors (say 3 or 4) contain a value in
> order to use CMYK? Is it possible to use only 2 colors? Does this
> situation have anything at all to do with the colors settings? I'm
> using CS on a PC if that matters at all. Thanks in advance. Paul
>

You're probably in RGB mode. Change your image to CMYK and the numbers
will stay put.

RGB mode does not directly store the CMYK values, and must convert them
to and from RGB, which spreads the data into all four CMYK channels.

--
Mike Russell - www.curvemeister.com
pmind

2007-06-20, 6:15 pm

On Jun 20, 10:46 am, Mike Russell <mike-remo...@curvemeister.com>
wrote:
> pmind wrote:
>
> You're probably in RGB mode. Change your image to CMYK and the numbers
> will stay put.
>
> RGB mode does not directly store the CMYK values, and must convert them
> to and from RGB, which spreads the data into all four CMYK channels.
>
> --
> Mike Russell -www.curvemeister.com


Duh, indeed it does stay put; thanks Mike! I guess my head is still a
little foggy from vacation!

tacit

2007-06-20, 10:15 pm

In article <1182348032.603240.209930@k79g2000hse.googlegroups.com>,
pmind <pmaslanka@aol.com> wrote:

> Can someone please explain...I have just created a solid color
> adjustment layer with the values of C=90, M=57, Y=0, K=0 (per customer
> instruction), however when I double click on the adjustment layer I
> see that the values have changed to C=91, M=61, Y=5, K=1. Every time I
> change the values to use only 2 colors, they change back as described.


You are working in RGB, not CMYK. If you want to use specific CMYK
values, work in CMYK.

--
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http://www.xeromag.com/franklin.html
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