Specifying color using Lab values

[gordo]

I'd love to hear your thoughts on specifying colors in apps like InDesign using Lab values instead of cmyk for print production.
Good idea? Bad? Concerns? Choice of rendering intents etc. is anyone doing this?

Thx, gordo

 

[Deleted member 16349]

I'd love to hear your thoughts on specifying colors in apps like InDesign using Lab values instead of cmyk for print production.
Good idea? Bad? Concerns? Choice of rendering intents etc. is anyone doing this?

Thx, gordo

Yes, I think it is ultimately a good idea and not just for special colours. Device dependent definitions of colour are problematic. The technology is potentially available to make this fairly easy for the industry to use Lab values.

At least that is what I think but I am not a practitioner but mainly viewing this from a theoretical perspective on what I suspect is the eventual outcome.

I think I also read on a Linkedin post from John Seymour that the standards groups were considering moving towards defining targets based on colour tolerances instead of TVI or similar non colour parameters. Not 100% sure if I remembered this correctly but it seemed to be in the right direction.

 

[HarveyDunn]

I'd love to hear your thoughts on specifying colors in apps like InDesign using Lab values instead of cmyk for print production.

My understanding is that this is happening whether you know it or not. If you specify a CMYK build, Adobe products convert it to LAB (using the conversion appropriate for the color management settings you have chosen) and store it that way.

 

[almaink]

It is messing with my workflow. My RIP does all my spot to CMYK separations so I don't get different color breakdowns from different applications, and it uses alternate space CMYK values to do it, if LAB is the alternate, it rips but with different values. I get a PDF from one of the new CS applications and it contains an EPS with LAB values instead of being a Spot Color with CMYK alternate color space and I get a logo that doesn't match what I've been printing for 20 years. Easy to fix but if I don't see it it's not. This burned me one time so now I look for it, still a PITFA and I don't like it as it adds to things I have "fix". I've told everyone I can that send me PDF's from InDesign to uncheck the "use standard LAB values for spots" in Ink Manager and I hope that helps.

 

[gordo]

My understanding is that this is happening whether you know it or not. If you specify a CMYK build, Adobe products convert it to LAB (using the conversion appropriate for the color management settings you have chosen) and store it that way.

For offset, if you specify a CMYK screen tint build then that is what you should get - there is no automatic conversion to Lab.

Best, gordo

 

[Jim Restle]

We've run into some serious issues trying to run PDFs through our ink optimization (CGS Ink Saver) software. Reds come out green, etc. The main culprit seems to be Lab spot colors in AI, converted to process in InDesign by customer. So we see a CMYK PDF, and everything seems to be good to go. Files that contain spot Lab colors, or if we're not certain of source, are not run through ink optimization.