Problems with spot color in printing

[gninneh]

Hi all,
we have a Canon ImagePress C6010VP with an Imagepress CR Server A7000 (CREO-RIP). I am really confused about somethings regarding the output of spot colors after editing them in the RIP's spot color editor.

I test print from the editors variations palette, and match my color to be almost perfect compared to the Pantone Swatch Book. But when I print the actual PDF it comes out hugely different than the testprint from the editor.

I've tried printing from Acrobat, directly from the source (Illustrator) and from Indesign (placed as PDF, EPS and AI) as well as PDF to a hotfolder on the RIP, but it just seems to ignore my predefined spot-adjustment in the RIP's substitution)

I've never come across this problem before although I've adjusted a bunch of other colors for other jobs with no problem.

My suspicion was that it must be the file, some element affecting the color, but when I tried to remove all other elements than the background color (Pantone Gray 429) it still came out different than the sample from the spot-color editor.

What gives??? I mean the printer CAN reproduce my color of choice when I'm adjusting but not when the actual job is sent to the RIP.

Anybody have any thoughts about what I can try?

 

[tommrz]

I am not familiar with that rip but it sounds like it may be a naming convention problem. Does your rip rely on "named" spot colors? Make certain the color name in the file matches exactly the color name in your library or it wont pick up your custom mix. I assume your color management is only allowing your profiles to adjust process elements and is applying library color mixes to your named spot colors.

 

[gninneh]

Hi tommrz, yes my RIP color and my "document-color" is the same, and I also double-checked by adding 50% magenta to the mix, just to see that it responded, and it did.

 

[caveman]

Does your RIP have more than one table for spot conversion? If yes, the tables priority may be your problem. Instead of reading the table with your edited spot it reads another table with the inaccurate values. You mentioned you have done this before. If you create a new file with the desired color how will it print? Can you try to edit a different spot and see if the output is the same when printing from the editor or form a file. This will help determine if the problem is file specific or spot specific.

 

[gninneh]

No the RIP has only one table for substitution, and yes I've tried to create a file with only the specific color in a new document, but still the same result. My take on this is that it IS file specific, since the straight output from the RIP's spot-editor looks fine, but as soon as it is coming from a PDF sent to the RIP it messes the color up.

"The game is still afoot" as a opium-ridden detective would have said.

 

[D Ink Man]

Grays....... The most difficult of any spot colors in any process system.
Please try again to learn. Try two other spots. Suggestion; 421 and 7689. How's the color? Just a thought. D

 

[BarbWPP]

Has something else perhaps changed so that the spot color is getting re-defined as process before it goes through the editor? Acrobat keeps such changes until changed again, but you probably know that by now. Other apps are less stubborn, so I suspect some setting at the printer/rip?

 

[pacart]

I know that when printing from Indesign you have the options of:

Composite Leave Unchanged
Composite Gray
Composite RGB
Composite CMYK
Separations
In-Rip Separations

So when I print to my digital press, I can have different effects on the spot colors depending which option I choose. I think the best option for spot colors is "Composite Leave Unchanged"

Oh, this option is available in the print dialogue under "Output"

 

[Paul Simon]

Check to see if the output profile is the same. You might be changing the PLAIN profile and printing to a GLOSS profile.

 

[D Ink Man]

Check to see if the output profile is the same. You might be changing the PLAIN profile and printing to a GLOSS profile.

Tis GRAY. D toughest. Trust me. D

 

[gninneh]

Check to see if the output profile is the same. You might be changing the PLAIN profile and printing to a GLOSS profile.

Hi Paul, earlier when we used Fiery Rip that would be the sure culprit in my opinion, but in the CREO the spot-definitions are "profile-less" as long as you make correct paper-catalogs (measured with the robot-thingy) the press should (in theory - depending on the humidity an so on) display the edited spot the same way on all papers.

I've now taken the rebellious route and edited the spot to look right when printing the PDF in question, and took a note of the corrrect colormix to use if the same color is used by another customer, maybe that PDF will behave in a different matter.

Thanks for all suggestions people