On 01/08/07, publied technical account wrote:
> hi Theo,
>
> thank you for the answer, but i find a bit frustrating ever time to
> calculate Coord_color/255*100 and ever i've defined a color with
>; decimal
> (D) or hex (#) coordinates. mental-laziness issue. ;)
>
> give some other question in cmyk color definition on winPgs
> 5.0.3.4pro.
>
> i let these cmyk-coordinates for the muddy green color:
>
> name: muddy-green tint:100%
> type: process, print:overprint
>; model:cmyk
> coord:47%,59%,99%,42%
That can't be right. There is more Magenta and Yellow than Cyan, so that
color would have to be a brown, not a green.
Next, you have 42% of all three color inks. When defining a color in
CMYK, one should take away the lowest percentage, so that one ink is
zero and the other two define the hue. The black ink then gives the
"darkness".
So that gives us
42-42 = 0 C
59-42 = 17% M
99-42 = 57% Y
42% K
which is indeed a mud brown, and shows as such on the screen.
In other words, you have so much ink there that it must print black or
nearly black. 42% each of CM and Y is the same as 42% K . Use the
figures I give above, but increase K by 42% to 84%, and you have a near
black.
Possibly Photoshop does automatic undercolor removal?
>
> once i've defined the fill-attributes of any objects (line and square)
> with muddy-green color, on screen i'm seeing it black instead of my
> muddy green.
>
> printing the document the muddy-green elements are all black and not
> muddy-green.
>
> but, after i've adjusting the percentage of fill-color (i put it for
> example a 81%), the color on screen and on printer works good. they
> aren't black.
>
> the strange is that the same muddy-green 
100% of tint (and not 81%
> of tint) on photoshop work fine on screen and on printer (quite like
>; the 81% of tin in pgs).
>
> do you know if give some differences between the handling of cmyk
>; color in photoshop and winPgs?
>
Photoshop may be changing what you ask for when it doesn't make sense?
Regards
--
Don Cox
doncox%40enterprise.net">doncoxenterprise.net
.
