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I work in prepress production at a publishing house and often times only have access to .PDF cover files which contain spot (pantone) colors from their former offset printing days. Because I set up these files for digital printing, spot colors are NOT an option.

What is the most professional way to convert these spot colors to process? I see features in Acrobat that claim to map them to the (nearest?) process value but I wish to understand more about this acrobat feature and if more precise alternatives exist, pitfalls to avoid, etc.

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The thing is it depends. CMYK has a different possible range of colors than spot colors, this range is called color gamut. So it may be that your chosen spot color is outside the gamut of your regular CMYK printer.

This gets you in a bind, since now you need to decide what alternate color to use. For this you need to have a colorimeter to decide what your equipment is capable of and so that you can soft proof the color on screen, or profile your printer. You may be even unluckier, the Pantone color may be outside the gamut of your monitor.

You could also use a more advanced printer with several more colors than the standard CMYK, like a indigo digital press that could do 97% of your Pantone chart somewhat accurately.

However, its hard to get you good answers as we dont just know. For example Why is it you want to print CMYK?

  • Cost, if so then a printer capable of your range may be more expensive than to use Pantone (or may not).
  • You need to do this with a locally available printer. Again now its a question of what that printers gamut is.

In the end theres no safe way to do this unless you know whow the color maps into your gamut space. Where you need to print CMYK and why!

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If you only have access to the PDF and can't really open it in Illustrator/Photoshop to convert the spot colors (since most designers don't vectorize their fonts...), you can convert everything to CMYK in Adobe Acrobat Pro with the Preflight.

You can use the "Preflight" feature and create a profile to "fix" files; it will verify if you have any other color mode in your PDF but will also offer you to fix this to CMYK. So far, I always had excellent results with this.

There's already profiles you can choose from and that you can modify as well if you don't want to add any color profile to your conversion or remove all overprint black, increase line thickness, etc. There's lot of options. I find it very practical to have my own custom profiles with basic touch-ups only; I have one for grayscale and one for CMYK, but you can create as many as you want and it's a very quick way to solve your issue.

Of course, Adobe Acrobat Pro will use the default values of the Pantones, but that's the price to pay for the designer who sent you these files and didn't convert them; and frankly, there's so much variation of colors on digital press, there's no point in going crazy with the conversion as long it looks very similar to the original Pantones... which is usually the case.

You can always verify the result using the "output preview" tool that shows you the color values on your file. That's something you might want to verify if you have to convert an ad for Pfizer, for example!


PS: Converting the pantones yourself with this is still better than sending them to the digital printer and let it convert them. From experience, I can tell you the colors look way closer to the real color if you do it yourself this way; A lot of digital printers need to have their "pantones equivalent" calibrated and not many do it because it's a demanding job and not really worth it. Their Pantones equivalent is also most of the time very "off".


Preflight with Adobe Acrobat Pro and convert Pantones spot to cmyk

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What is the safest / most precise

I am completly discarding one option. The cheapest.

Then the safest and more precise is to correctly calibrate your digital print with specialized hardware and software, and to keep a very tight methodology and process.

I just will give you a starting point:

http://www.xrite.com/color-measurement-products

Becouse you need to make decisions on your workflow.


But there is an issue here. The digital printer's software should have a minimum color conversion software and drivers. In theory you can send a pdf with spot colors all arround, and the printer software and color profile should make the conversions before printing it. Spot colors should be an option, the safest option inclusive.

Again. You should have a specific profile on your system. You also can provide it to your customers.

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