Help with determining PANTONE swatches accurately in CS3

[alaquinas]

I've recently designed a logo for an event. It's a 3-color design done entirely using process colors. The client would like the PANTONE equivalent of each color, however, and I'm having a lot of trouble figuring this all out (I'm a bit of a prepress newbie).

First of all, I have a lot of questions about the LAB view vs. CMYK view for spot colors in Illustrator:

1) The difference between the two is HUGE. In CMYK view, there is less subtlty, but the colors are vibrant and versatile. In LAB view, I can access certain colors I can't otherwise get, but most of the palette is desaturated and muddy. Is it supposed to be this way?

2) Supposedly, the LAB view for spot colors is relatively new in Illustrator. Considering how far off-base the CMYK versions of each spot swatch is, how was anyone getting work done before this feature was added? I don't understand how I could have even hoped to do spot color work using the CMYK swatches in older versions. They're entirely different colors in many cases. I must be missing something.

3) Is it accurate to say that, monitor calibration notwithstanding, and all other things being equal, the LAB view of a given spot color is more "accurate" than the CMYK version? If this is the case, the PANTONE uncoated library of solids is incredibly dull and muddy, because that's how it looks in LAB mode. I've been browsing a physical PANTONE book as well, and the colors don't appear to be nearly as bad in real life. My monitor may not be perfect, but I can't believe it's so poorly calibrated that the colors could look THIS different.

4) When viewing my work in LAB view, one of my colors translates perfectly from CMYK, while another doesn't even come close when attempting to match it with a spot color. In CMYK view, it's reversed-- the first color looks terrible, while the second actually comes pretty close. Which version can I trust? They're total opposites, making the final selection of a single swatch impossible. I'm not sure what to give my client-- if they're using an older version of Illustrator (which is likely), they'll have to see this in CMYK mode, and it will look terrible. Even a PDF I exported doesn't look right in Acrobat. How should I be approaching this?

As you can see, the seemingly simple task of selecting PANTONE swatches for 3 CMYK colors has turned into a bit of a mess. Any help with these confusions of mine would be hugely appreciated.

Thanks!

 

[jmgalvin]

The pantone system is based on users owning the various Pantone books: Solids (spot), Process, and Bridge (solid to process comparison). These allow you to see colors as they will show on a printed page, from a press or professional proof printer.

Bridge gives you Pantone's best estimate of the shift between spot and process. For some colors, the shift is minimal. For others, it's immense. It's near impossible to determine this stuff without the books. No matter what you do, your screen (RGB) will not match all, even many, of the colors accurately, even if calibrated with an external calibrator. Hence, the printed books.

A set like I described runs $300. If you're in the print design business, it's near impossible to live without them.

Using OSX 10.3.9 & 10.4.11 on a G4, G5 & Intel Macbook

 

[apepp]

...yes the old cmyk to spot and spot to cmyk debate...

...it's a big area to bend the mind around...

...getting accurate on screen spot color renders is tricky, which is why it is the standard recommendation to have the pantone solid books and the pantone to cmyk books, or a printers target proof. Probable your clients monitor will display color quite differently...

...even the cmyk equivalents pantone provides are questionable with some colors, and in fact over the years pantone have even changed these cmyk values (the latest versions are in the Pantone Color Bridge Libraries) to supposedly create a better match. So even pantone know how problematic it is to achieve a close match between cmyk and some spot colors...

...some spot colors can be achieved pretty close in cmyk, but not all...

...a while ago hexachrome printing was introduced by pantone whereby cmyk and two extra colors are used (orange and green), known as CMYKOG. This process allows a much bigger color gamut, meaning many more spot colors can be achieved using 6 inks rather than just 4...

...hexachrome printing is in limited use, and also requires designers to use RGB values tagged with an ICC Pantone profile, which is then converted to 6 colors in a capable RIP...

...so for the rest of us, CMYK is all there is, which is where it becomes important to explain to clients that a calibrated proof from your chosen printer is always acquired before committing to print a job and if printing in spot colors you need to either have a wet proof (expensive) or provide them with a pantone book to mull over what colors they prefer...

...using lab value spot colors is recommended in a properly color managed workflow, using accurate device profiles, if the profiles aren't correct in the workflow then you could get poor results by using lab. They will also look different on output if using old artwork having the cmyk equivalents of the same given spot color...

...for on screen, when you turn on overprint preview, illustrator and indesign uses lab to display, and also when simulate overprint is turned on in the print dialog for output to a desktop printer...

...ensure your color settings are the same across your adobe suite...

...using photoshop can help in getting a cmyk color to a spot color equivalent, but this can be very hit and miss and is governed by the rendering intent in the color settings dialog. In the color picker you would type in your cmyk values, then choose either the solid or uncoated library...

...a visual comparison would also need to be made using the pantone books...

...photoshop uses lab values for spot colors, so when placing a photoshop file in illustrator or indesign with a spot, they could appear to display different from one app to the other, unless you specify lab in indesign and illustrator to match photoshop or turn on overprint preview in illustrator or indesign...

...to get a lab color pdf file you need to specify in the indesign ink manager to use lab values for spot colors, and in illustrator the lab values in the swatches flyout menu under 'spot colors...'

...with all being said, trusting spot color renders on screen is tricky really, be it lab or cmyk display, however out of the two, lab would be more accurate for output, so long as you have a well color managed workflow in place, otherwise use the pantone bridge library for cmyk output of spot colors...

...in the end though, there is no real substitute for a pantone solid book, pantone solid to process or a printers contract proof being obtained...

...not is all as it seems, it is not really a simple task in the slightest, printing is not an easy game. The same spot color on different substrates looks a different color, and also one pantone book can look slightly different to another, especially old pantone books compared to new ones. Even then I have come across the latest pantone books looking slightly different when compared...

...so as a designer tricky color decisions need to be made. As you have some arbitrary cmyk values, you could use the photoshop method to find a close pantone, then look in the book. Discuss with your client if they are happy with those pantone colors to be used...

...at the moment you have painted a wall using a color from one manufacturer, and are now trying to use someone else to get a close color, you might get near but a difference is likely inevitable...

Andrew