CMYK to CMYK Transformation in Photoshop

CIECAM wrote:

Probably, some graphic artist does not know what is tagging or embedding or converting colors. And it boils down to color management system.

You're absolutely right, CIECAM. But even if the designers or prepress specialists know how to tag, embed or convert colors, if they're using Photoshop to do this then the results may still be problematic especially with the transformation of:

a] CMYK tints & screens;
b] Black only texts; and
c] Grayscale photos;

That's why you're right by saying that some sort of a color management system (CMS) is needed.

Photoshop's way of a CMYK to CMYK transformation will convert black only elements into 4 colors.

Because from the original CMYK (US Web Coated) Photoshop will convert this to its internal profile connection space (CIELab or X,Y,Z) then onto the destination CMYK (ISO coated). Thus, the results are at times unacceptable.

That's why we need to have a 3rd party.....a CMS. Because many CMS have a device link function.

With this the source color is transformed to the destination color via Device Link, and not using a profile connection space. Ergo, the values of CMYK photos, vectors are transformed but the black texts, screens, tints....will remain black only.

So many high-end color servers are there but it also has an incredible price tag (eg. ALWAN CMYK Optimizer, OneVision's ASURA, etc.)

But cheaper ones like Acrobat plugins I mentioned in another thread can also be used with acceptable results (pdftoolbox4, Apago PDF Enhancer, Heidelberg Color Editor, etc.).

thanks, for this thread. just on time thinks this is the reason why I have such trouble in color matching, now I know. Btw, I am a press operator (digital), used to be a spectator of this forum, I just cant find anything to share I am still new with the industry and still learning.

yap, that would be great!!!

Buhayin ko lang itong thread na ito, para may pag-usapan.

CMYK to CMYK conversion in Photoshop will work fine. A simple logic of where do graphic artists create their bitmap photos will point out that the CMYK to CMYK conversion in Photoshop will give you no problem. Use "convert to profile" command in Photoshop.

If the file is a PDF, common sense will tell us not to open the file in Photoshop. Open it in Acrobat, then open the photos in Photoshop and convert it to desired icc profile or even custom GCR separation.

Sorry guys, I just wanted to point out that small printers who can not afford CMS could still do things that can yield very good result. CMS with Device Link is very expensive. I think the real benefits of CMS with Device Link is its ability to use maximum black GCR to save inks and yes it's very fast.

And I strongly recommend for small printers to upgrade to Acrobat 9 Pro if your workflow includes PDF.

For the sake of argument, hehehe.

I think I'm just brave enough to do things in my way as tools are not available. Maybe lucky enough to have good results and clients do not complain.

EPS or TIFF, I used the combination of Illy, PS and Acrobat to fix it.

FWIW, how do you think CMS convert CMYK to CMYK without affecting the the black channel? My wild guess is only the dot gain is being changed to fit with corresponding paper stock and ink. So, figure how I do it in PS (hehehe, I know you knew).

Tools are really a must. But for printer with limited resources, there are work around.

Oh and before PDF, EPS and TIFF are the standards.