any way to keep Black only screens Black only

[DavidMa]

Here is a question from one of my co-workers:

Is there any way to keep Black only screens Black only, in a cmyk file when color managing in Photo shop? for example. I have a cmyk file, filled with 50% black. when color managing in PS it converts to a 3/c mix with no black. is there a way to preserve the black?


any you guys got a hint?

 

[Louis Dery]

Here is a question from one of my co-workers:

Is there any way to keep Black only screens Black only, in a cmyk file when color managing in Photo shop? for example. I have a cmyk file, filled with 50% black. when color managing in PS it converts to a 3/c mix with no black. is there a way to preserve the black?


any you guys got a hint?

Hi DavidMa,

The only way of preserving Black in Photoshop is to use ICC DeviceLink profile. Beware that it is only with Photoshop CS4! It is now compatible to use ICC devicelink profile.
To create ICC device link profile you need specialized software.

Louis

 

[dimitri]

Is the screen defined as a spot color?
This should be happening because you have light GCR settings on the ICC profile you are using for the conversion in Photoshop. I think your question is related to my question on another post, so I think I can describe the problem but I have no perfect solution.

Still, what are the devices you are trying to color match? Even with light GCR settings the CMM would be trying to use some black unless the black colorants of each device are WAY too different in terms of CIELAB, or the black is shut off from even a 50% dot area. I'd say look at the how the ICC profiles are made. If I am correct, increasing the GCR would result in a CMYK instead of a CMY representation of the screen, but that should not be good enough for most cases either.

The other 'solution' to device links would be to manually work on the image. That is, apply no ICC color management, no ICC conversions, and preserve the CMYK values throughout the workflow.... but good look in terms of color.

-Dimitri

 

[meddington]

Couple of options as long as you don't mind touching the images after conversion. You could simply convert the image, then history-brush the desired areas back in black. Can't batch process this though. Another is to mask desired area and channel mix. Could be batched if masks cut up front. You could also convert the image twice, once using a black only profile, then merge in PS (some create drop shadows this way and plop both images in layout app).

Obviously the ideal for channel preservation is DVLs as Louis indicated, but maybe the above will limp you along til then.

 

[DavidMa]

thanks for your help guys, I'll pass all the info along.

cheers,
David

 

[Werby]

I know this isn't a helpful response, but if you are keeping black only areas black only, then you are not really color managing them. For instance, quite possibly the target colorspace you are trying to convert to has a different pigment color than the black in your proofing device. In that case the only way to get the correct "color" to your black is to contaminate it with other colors.

All the suggestions are good ones, and using a profile with high GCR will minimize the contamination, but you've got to ask why you are converting the file in the first place. If you are trying to get one device to match another, your best results involve contaminating your pure blacks.