CHROMiX

Ink limiting, linearizing, total ink limit

I have built enough bad profiles to know the importance of channel and total ink limits and linearization. I would like to be more confident on how to achieve the best possible of each of these.

My current view is to do channel ink limits first (looking for the point between patches where there is minimum gain in saturation/density or the occurance of spectral chroma hooks).

Second- to do total ink limit. Here I am a little less certain of the process. Any Suggestions for a good TIL target- I have not found a one as yet. What should the patches be?, CMY or CMYK…? Thoughts on measurement as opposed to visual inspection.

In one of my rips (ColorBurst) it has setting for “Total Ink Limit” 0 to 400% and a “Preserve Black” 0 to 100%. Can anyone explain that please?

Thrid: once I have set my per channel ink limits and my total ink limit (and my percentage black??)- Linearize (most of the lin programs are delta E lins) the channels.

Fourth: To build in some headroom for relinearization - throttle back the ink limits by 3 to 5%. Is this suggested on the individual ink limits or the total ink limits.

Any other suggestions or comments? THANKS IN ADVANCE.

Your procedure sounds solid in general. People have different purposes in setting up a RIP. If you are using it to proof a specific device, then we usually limit the ink so that the proofer is only just capable of reproducing the color of the press. This way the printer is more stable, ink is less costly, etc. Others want to maximize their gamut. I am guessing you are looking to maximize your gamut, but still have a stable printer that is easily maintained as far as linearization goes?

I think you have ColorThink Pro? People who are doing this kind of analysis of their workflow will have CTP to help with a lot of these tasks. There is a procedure in the Guide for Evaluating Optimal Device Ink Limits

Evaluating Device Linearity gives you a visual representation of the primaries and secondaries so you can see those chroma hooks and where you run out of any productive increase in gamut.

Thanks Patrick

Kirk

patrick… coming back to that ole topic…

im just realizing that with EFI fe. you limit your inkrestrictions already towards isocoated V2 f.e… that will like you say, too get me a stable and least inkusing proof profile…

but!.. what about my spotcolors…? dont i “loose” some of them?..

or how does the RIP handle that?

Hi…
Yes, if your image has spot colors that are out of gamut for the CMYK in that profile, then you won’t be able to hit them right on, but the RIP will do its best to get close. That is why the user has a choice for how aggressive the color settings of the RIP should be.

In your case, you have 7 colors to limit and linearize if you’re using the RIP, but you would have to make the same decision with your extra colors: the Red, Green and (it looks like) Purple if the RIP gives you control over them.