Adobe Illustrator - Illustrator with strange color behaviour

Author

Illustrator with strange color behaviour

Jan Thogersen

2006-04-08, 10:15 pm

Hi there...

My girlfriend was making some drawings in Illustrator and had to color
match some areas in the drawing with pieces of fabric so when the
drawing was printed on her Canon I6500 Injet the colors would match (as
much as possible).

So I wanted to help her and made a photoshop picture with a lot of
rectangles in different colors and their RGB value written beneath so my
girlfrind could match up the fabric with a printed version of my color
scheme.
It sounded like a really good idea at the time but it's apparently not
that easy... When she printed my color scheme from photoshop and then
tried to print an illustrator drawing using some of the RGB values from
the color scheme they turned out different in colors!

So I got the impression that Illustrator and Photoshop managed the
colors different. To prove my thoughts I made a Illustrator document in
RGB mode... Then copied 4 rectangles with different colors from
Photoshop into the illustrator document (These rectangles are still in
raster format). Then I made 4 rectangles in illustrator (in vector)
using the exact same colors as used in the raster rectangles. I even
used the Eye Drop tool to make sure that the RGB value would be the same.

So my end product was 8 rectangles in the same document. 4 of them in
raster and 4 of them in vector. All paired up 2 and 2 in color.

Now the strange part... because when this document was printed there was
a significant difference in the colors between the raster and the vector
even though it was made in the same RGB values and the same document!

What is the problem here? How can I print out my color scheme so it's
possible to use the same RGB values in illustrator to get the same
result on the printer.

Hope I made my self clear! It was a bit tricky to explain but hope I
managed :-)

PS. Both Photoshop and Illustrator was setup to use RGB mode.

Thanks in advance! I would really appreciate any hints...

Best regards
Jan

Doug Winger

2006-04-09, 3:15 am

In article <GrXZf.151$ZQ1.20@news.get2net.dk>,
Jan Thogersen <jan@fishcorp.dk> wrote:

> [Clipping]
> So I got the impression that Illustrator and Photoshop managed the
> colors different. To prove my thoughts I made a Illustrator document
> in
> RGB mode... Then copied 4 rectangles with different colors from
> Photoshop into the illustrator document (These rectangles are still
> in
> raster format). Then I made 4 rectangles in illustrator (in vector)
> using the exact same colors as used in the raster rectangles. I even
> used the Eye Drop tool to make sure that the RGB value would be the
> same.
>
> So my end product was 8 rectangles in the same document. 4 of them in
> raster and 4 of them in vector. All paired up 2 and 2 in color.
>
> Now the strange part... because when this document was printed there
> was
> a significant difference in the colors between the raster and the
> vector
> even though it was made in the same RGB values and the same document!
>
> What is the problem here? How can I print out my color scheme so it's
> possible to use the same RGB values in illustrator to get the same
> result on the printer.
>

One possible factor that causes such problems is that the printer
driver's conversion from Ilustrator's "pure" postscript RGB color
models to the printer's CMYK color space as compared to using the
encoded raster's values. Transcription/translation of ps color code is
often a weak point of non-postscript machines, often making color
matching a problem. Using CMS software is almost a must, and calbration
crucial.

Photoshop's ability to internally synch color models using profiles
makes that less of a problem, though color synchronization can often
still be somewhat of a black art. Things like Apple's ColorSync make
the job somewhat easier, but translating from one color space to
another almost always causes "purity" problems and color shifts in
output unless your color management is set up properly. Also consider
that Illustrator's normal default color model is meant for producing
seperations for printing and not for direct output to a printer- which
is why they have cleverly added the ability to set "soft proofing"
color profiles into the production tools.

Now that I've babbled on about that, one possible solution is to NOT
use RGB as a working color space. That's for display purposes, and will
almost always translate poorly to a printer's CMYK when sent directly
through the (non postscript) driver. Calbrating your monitor and
instituting a CMS policy for your applications will also help prevent
similar problems down the line. Make sure you've set your CMS/color
profiles to match the printer you'll be using.

Sorry I can't be of more specific help in this case.

- Doug

Jan Thogersen

2006-04-09, 6:16 pm

Doug Winger wrote:
> In article <GrXZf.151$ZQ1.20@news.get2net.dk>,
> Jan Thogersen <jan@fishcorp.dk> wrote:
>
>
>
>
>
> One possible factor that causes such problems is that the printer
> driver's conversion from Ilustrator's "pure" postscript RGB color
> models to the printer's CMYK color space as compared to using the
> encoded raster's values. Transcription/translation of ps color code is
> often a weak point of non-postscript machines, often making color
> matching a problem. Using CMS software is almost a must, and calbration
> crucial.

Hi Doug,

You answer gave me some clues about how to fix the problem. And what I
found out was that the printer driver treats raster and vectors
differently. In the printer driver settings there is an option to let
the driver make some color correction on a picture and that was the
thing causing my troubles. If that options was disabled then Photoshop
and illustrator started printing the same RGB values with same result on
papir.

So thanks for your kind help.

Best regards
Jan