CMYK Coated to CMYK uncoated conversion

[bhm8hwcm]

I was wondering if there is a good way to prepare print jobs for printing on uncoated stocks. Jobs come in being prepared with the standard SWOP Coated V2 settings. What is the best way to prep them for uncoated.

Do you open all the images in photoshop and lighten them? What about vector objects?
Do you apply a dot gain curve at the rip?
Or using Acrobat can you simply do a color conversion for all colours to a new destination space like Web or sheetfed uncoated?

Or is there other ways, or software avaialbe? I do not run much uncoated (less than 10% of jobs).

How do you then soft proof PDFs intended for uncoated. Tag everything with ICC uncoated profiles?

Thanks.

 

[gordo]

Re: CMYK Coated to CMYK uncoated conversion

Run the inks at slightly higher SIDs (if you can) and apply a dot gain compensation curve to the plate designed to tonally align your uncoated work, as much as possible, to your coated work.

gordo

 

[jlind]

Re: CMYK Coated to CMYK uncoated conversion

Gordo:
Do you really mean that he should run higher densities on uncoated than on coated paper? In all the best practice guidelines, which I know you are aware of, this is never the case. Uncoated densities are always less than coated densities. What do you want this guy to do to "tonally align" the two print conditions? Best print contrast, shadows still open, felsh tones not muddy, no color casts?

John Lind
Cranberry Township, Pa
724-776-4718

 

[gordo]

Re: CMYK Coated to CMYK uncoated conversion

Hi John,

Yes higher SIDs with the caveat that I included "(if you can)"
RE: "Uncoated densities are always less than coated densities." Yes they will be. I'm just suggesting that he run the densities as high as he can (while maintaining stability, no offsetting, etc.) to optimize the press work as much as possible.
For tone alignment, this is standard TRC methods.

gordo

 

[rich apollo]

Re: CMYK Coated to CMYK uncoated conversion

Barry, any and all of the ideas in your post are valid. I like to color manage in Acrobat, now, because, as you cited, you need to work the vector-based elements, too.

Curves for uncoated will be different than for coated stocks - in addition to appropriate color management.

Going from Coated v2 to an uncoated colorspace would be the technically correct procedure, but it can be tough to find, or build, the correct uncoated profile. Another tactic would be to go from Coated v2 to another profile built from the Coated v2 data (TR001) with lower TAC and a white point altered to match the uncoated paper.

rich

 

[pilotdave]

Re: CMYK Coated to CMYK uncoated conversion

Hi Barry,

This is where a CMYK Conversion software program comes into play, like Alwan CMYKOptimizer or GMG ColorServer. These products use DeviceLinks to convert the PDF from a source CMYK Profile like USWebCoatedSWOP to a destination CMYK Profile like ISO Uncoated, or a custom one based on your press. In the process, this conversion allows you to protect you channel integrity, keep black as black, as well as all primaries, secondaries and more. It will also reduce the Total Area Coverage and perform a color conversion as well as applying an intelligent degree of GCR to allow for more stability on press, quicker make ready and ink savings. I have actual press sheets with the digital files that show the results if you are interested.

I know of over 70 accounts using this technology, although many do not want you to know because the benefits are great, but I can provide you with as many references as you would like,

Dave

 

[Louis Dery]

Re: CMYK Coated to CMYK uncoated conversion

Hi Dave,

I know many many existing prepress workflows, compatible with ICC DeviceLink profile. Unfortunately, many printing or prepress companies don’t know that they already have already part of the solution. They simply need a software to create good ICC DeviceLink profiles (with capability to do ink reduction, GCR, special color handling, etc.) and use it in THEIR existing RIP server!

… "although many do not want you to know because the benefits are great".


Louis