Quickly Convert Digital RGB Output to Print CMYK With Adobe Acrobat

[Mike the Print Man]

Video I did answering a question to a post on Reddit. Designer was using InDesign mostly for digital content so all their swatches were in RGB, but occasionally they wanted to output to CMYK and maintain their clients branding standards. I made a little example of how this can be achieved via a Acrobat Preflight.

Hopefully someone finds it useful.

 

[Dov Isaacs]

This video provides an absolutely excellent tutorial on how one can readily convert colors in Acrobat Pro. The tutorial uses Acrobat's built-in Preflight although similar capabilities are available in Callas pdfToolbox (which is actually the basis for Acrobat Preflight) and Enfocus PitStop.

The major issue I have here is not the techniques for after-the-fact (i.e., creation of PDF) conversion of colors in a PDF file, but the overall workflow involved here.

Let's start off with the color specifications provided in the original InDesign document.

Pantone 3005 C is specified as RGB=(0, 129, 200) with CMYK=(100, 37, 0, 0).
Pantone 137 C is specified as RGB=(252, 177, 49) with CMYK=(0, 34, 91, 0).
Pantone 426 C is specified as RGB=(0, 0, 0) with CMYK=(0, 0, 0, 100)
Pantone 355 C is specified as RGB=(0, 166, 81) with CMYK=(100, 0, 100, 0)
Pantone 192 C is specified as RGB=(238, 51, 78) with CMYK=(0, 94, 65, 0)

The big question is exactly what RGB and what CMYK color spaces are being referred to here. Is the RGB sRGB, Adobe RGB, P3, etc? Is the CMYK US Web Coated (SWOP) V2, FOGRA39, Japan Color, etc.? (The fact that the 2020 Olympics were in Japan would possibly lead one to believe that one of the Japan Color CMYK color spaces might be what was intended.

DeviceCMYK and DeviceRGB color specifications in this context are really useless and can end up with not only unexpected printed results, but also unexpected display results.

I ran my own experiments in InDesign using the provided Pantone colors specified along with the Pantone Solid Coated V4 Definitions. Part of the problem over the years has been Pantone's wishy-washiness in terms of actual alternate color definitions for what spot colors. The five spot colors specified would normally be printed using spot color inks. The actual “alternate color space” for these color is not any CMYK or RGB, but rather CIELaB.

If one wants to create content in InDesign with these spot colors being used, one should add the Pantone colors to the document's color swatches (specifying use of the alternate color space's LaB colors in the Pantone swatch). Leave the color swatches as spot colors (not process colors) in the InDesign document. Exporting the InDesign document as PDF allows you to either pass through the spot colors with the alternate LaB color definitions if the device (screen or printer) does not support the particular spot colors. Alternatively, you can export the PDF with the option of using the LaB color definitions only if you know that you don't have spot color inks. Both Acrobat and any modern PDF printing device knows how to deal with this and you will get much better printed results. (The same is true with PDF file display on screen). We most strongly recommend PDF export using PDF/X-4 standards when printing is either required or possible!!

I ran my experiments and have attached three PDF files using these Pantone colors and with the values I encountered.

To summarize, the actual US Web Coated (SWOP) V2 CMYK values were very significantly different than what was specified in your original InDesign document:

Pantone 3005 C specified as CMYK=(100, 37, 0, 0), actual SWOP CMYK=(100, 46.2, 38, 0.1).
Pantone 137 C specified as CMYK=(0, 34, 91, 0), actual SWOP CMYK=(0, 42.6, 100, 0).
Pantone 426 C specified as CMYK=(0, 0, 0, 100), actual SWOP CMYK=(76.3, 66.3, 60.3, 66.1)
Pantone 355 C is specified as CMYK=(100 ,0, 100, 0), actual SWOP CMYK=(100, 12.4, 100, 2.2)
Pantone 192 C is specified as CMYK=(0, 94, 65, 0), actual SWOP CMYK=(2.5, 100, 70.4, 0.1)

The differences between the “specified” CMYK values (no CMYK color space specified) and the reality of proper use of Pantone color definitions are in some cases dramatic. For example, Pantone 426 C is absolutely not “process black” but rather, a rich black.

The bottom line is that use of Pantone color definitions should be done with care, not on a whimsey. Use of ICC color management for content creation is really a must, especially when “brand color” is critically important (such as I assume it was for the Olympics.)

See attached PDF files as well as packaged (in .ZIP file) InDesign sample file.

- Dov Isaacs

 

[Mike the Print Man]

Dov, you are the GOAT! A very detailed explanation of the proper way to utilize and output those colors.

My video does not go in near the detail you explain above. I simply was trying to show a way to change out those colors quickly using a preflight profile. Yes, the glaring example is the use of PANTONE 426 C. The CMYK output is no where near the correct color. However, I was going off of what their branding standards specified in their document. Those colors were not chosen by me.

I wasn't thinking of going into that level of detail. I was more focused on helping the individual with their problem of swapping the RGB values to CMYK properly.

For myself I would never even design a file without specifying proper PANTONE swatches, but in prepress we come across all sorts of "interesting" files from day to day.

Thank you for your response and for watching the video. I think I'll have to keep those thoughts in mind when explaining the potential pit falls with improper use of colors and varying color spaces in some of my future videos that deal with color.