January 26, 2007

C vs. CVC -- a battle of Pantone proportions

As many of you already know, Pantone colors were once named with "CVC" and "CVU" after their numbers. These were to indicate Computer Video Coated and Computer Video Uncoated. But in the year 2000, Pantone switched to a universal naming scheme, using only C for coated, M for matte, or U for uncoated. But since the naming itself wasn't enough, Pantone also changed the actual color breakdowns, or CMYK representations of those colors. A new Spot to Process Guide was published as well.

Illustrator 10 was the first version of Illustrator to use these newer libraries (according to Adobe's licensing agreement with Pantone, Adobe is required to ship their products with the latest available libraries).

This opened the doors for a potential problem: If you opened an older Illustrator file that used an older Pantone CVC number, the CMYK equivalent of that color might not match the newer CMYK equivalents found in the newer Pantone C libraries that ship with newer versions of Illustrator.

In reality, if you are specifying a Pantone color, and are printing it as a spot color plate, the underlying CMYK values really don't mean much (except for proofing). But on press, everything will be fine, as those CMYK values are never used.

However, many designers use Pantone colors -- and those colors are many times converted to process later in the workflow -- either by another designer or by the printer. This can cause color shifts where the older and newer colors appear.

For this reason, the release of both Illustrator 10 and Illustrator CS also shipped with both the newer C libraries as well as the older CVC libraries, so that users could load and use the older CVC colors and migrate to the newer colors as they were ready to do so. Basically, Illustrator will allow you to import older colors in an unchanged state, and you can choose to manually move to the new colors -- thereby retaining the integrity of the older files.

However, InDesign chose to take a different route to address this problem.

As a page layout application, InDesign is used to aggregate content from other sources and applications. When you place content into InDesign -- for example, an EPS, a PDF, or an Illustrator file -- InDesign will look for any spot colors in that file and add those colors to its own Swatches palette. Now, if you already have a newer Pantone C color that exists in your file (say for example, Pantone 485 C), then if you place an older Illustrator file with a Pantone 485 CVC swatch, the result will be TWO plates in your InDesign file -- one named Pantone 485 C and one named Pantone 485 CVC. Because of the difference in the name, these colors will separate on two separate plates.

To prevent this from happening though, InDesign has code that can recognize the names of Pantone colors. When InDesign sees a Pantone CVC number, it imports it and merges it into the same swatch as the C number -- meaning if you place a file with Pantone 485 CVC into InDesign, that color is automatically merged with the newer Pantone C number -- and the result is a single plate. Which is nice. But there's one problem -- in this process, InDesign uses the newer Pantone C CMYK equivalents of the color. In fact, even if you import a CVC color into InDesign, and you don't even HAVE an exisiting C color in your file, InDesign will recognize the CVC number and automatically convert the CMYK equivalents to match the newer book color (the C values). This means there is no way in InDesign to preserve the older values, if you had wanted to. That means if you convert that spot color to process in InDesign, the color values will change -- and there's nothing at all that you can do about it.

You can argue whether InDesign's behavior is correct, or whether Illustrator behavior is correct, but the end result is that Illustrator and InDesign are not consistent, and you'll see different results depending on which app you print these files from. I should point out that Acrobat will mimic Illustrator's behavior here -- so printing from AI and Acrobat will give you the same result -- but printing from InDesign will result in something different.


BlueKDesign said...

If that wasn't confusing enough, the Pantone library that shipped with Illustrator 10 was wrong at the upper range 7500.

"Adobe Illustrator 10.0.3 PANTONE update - English

This update for Adobeᆴ Illustrator includes four PANTONEᆴ libraries:
PANTONE Solid Coated
PANTONE Solid Matte
PANTONE Solid Uncoated
PANTONE Process Coated

The first three libraries have corrected CMYK color values for Pantone colors 7492-7547.

The fourth library has been updated so swatches are set to Illustratorメs Global Process colors rather than Spot Colors."

Then, in Creative Suite, more problems:

332999 PANTONE Color Bridge library not available in Adobe Creative Suite applications

330728 CMYK values of PANTONE swatches are different in Illustrator CS and Photoshop CS

Pantone also updated the Solid to Process formulas - once in 2000, then again in 2005. Solid to Process is now Color Bridge.

See the "Learning to Love Pantone's new Color Bridge Guide" Seybold Bulletin, Vol 10 No 31, May 11 2005

Only use spot colors when you are printing a spot plate. In all other cases, use a process color. Use the Trumatch library or buy a printed book of CMYK swatches.

Anonymous said...

It really comes down to the designer controlling the software, and not the other way around. If you have to, type in your own CMYK numbers.

Another issue is using solid (spot) colors for process printing. I know sometimes it is unavoidable, but if working on a strictly process job and picking new colors (for example, not trying to match a logo color)--use a process-only guide. Pantone makes a nice, fairly inexpensive process-only guide with over 3300 colors in it. (There are other guides, of course.) Pantone's process-only guides are built into the software libraries too.

An exception to using process-only colors is when printing using (advanced) color managment. Then one might want to use LAB values in PS, AI, and ID; colors would be selected and left as spot colors.

Another exception to using strictly process colors is when printing to a color laser printer as the final output. Sometimes (you will have to test it), laser printers can get better matches to spot colors than the solid-to-process guide or the Bridge guide shows.

Anonymous said...

If you are converting to CMYK anyway, is there a reason not to convert the Spot color to a Global color in Illustrator (which assumably will do the conversion the way you want it) before importing the image to Indesign?

Unknown said...

bluekdesign - that's a ton of information. Thanks for taking the time to post that info here.

david - thanks for the added information. Always nice to see you here :)

beauw - as you know, all jobs are different. But many times, a designer will create a color as a spot, but only later will find out that it will be a process job (maybe the printer will make that decision). But my entire post was really written as a response to someone's question on another forum (the CTP list), who had recieved a PDF from a client with the said Pantone numbers in it. Upon bringing the PDF into InDesign for a few edits, the printer noticed that the Pantone values had changed. But doing the same thing in Acrobat or Illustrator resulted in no change at all. The printer had no access to the original source files (Illustrator, Quark, or otherwise). This post answered why the printer was seeing what he was seeing.

Obviously, as with ANY job in design (print, or web) -- you should always design your work to the specifications of your medium and workflow. Of course, we don't live in a perfect world, and therefore, we deal with all of these issues :)

Anonymous said...

good story:
Here's another nice little problem:
Illustrator CS uses Pantone libraries to change PMS to CMYK. Illustrator CS2 uses LAB values. And ofcourse Photoshop CS and CS2 also uses LAB values bases on the selected ICC profile. ;-)


Unknown said...

Actually Woz, that isn't quite correct. I spoke a bit about Illustrator and how it uses Lab values for spot colors in my December episode of my podcast (entitled Critical Color Control), but maybe a follow up post on this subject is in order just to clarify...

Anonymous said...

True, it it not exactly correct. I had to re-read my own origional article about Pantone, and to summarize it all up:
1) Illu CS uses pantone-to-cmyk values from Pantone
2) Illu CS2 uses both LAB and Pantone-to-cmyk from Pantone

–But the catch is: The Pantone to LAB values were also provided by Pantone. And we know Pantone has not always been very good at giving us the proper cmyk values. (This has changed now they printed their new 'Pantone color bridge coated EURO' using European ink ;-). Now they are fully ISO12647-2.– Before that they supplied Pantone libraries based on American ink.

However, I'd love to read (or hear) more on this subject as there are not a whole lot op people who actually know (or care) this much about the technology behind the programs. :-)

Anonymous said...

Perhaps Adobe & Pantone can put some water on these fires by PLEASE putting a link on library palettes that take you to the proper page at Pantone.com so you can see which book(s)/Bridge version(s) they're talking about along with updates/patches, etc.
Also, include a "report broken links/wrong values" button that sends the appropriate messages to the right people.
We've had hotlinks in software dialog boxes for MANY years, can we PLEASE have them here where they're really needed? /endRant /endVent
-Bill Carberry
Adobe Certified Instructor

Anonymous said...

Wow! I just ran into this problem with a client and google sent me straight to this post! It couldn't have been more effective in clarifying why I was getting such disparate results! Thanks for saving me time and helping me explain the cause of the slip to my client!

GloriaLila said...

Hey, I'm having some troubles with CVC and C Pantones... I'm trying to insert a logo with the old version of Pantone, how can I find the new Pantone for my client??? I'm using Freehand MX and Photoshop CS3, how can I find the new version of Pantone 294 CVC?? Is it easy as using CMYK? But what would be the new Pantone to replace CVC?