Hi Axel, Agree with Jon that Lab is the best way to define spot colors. Using Lab eliminates some unknowns in the workflow. For example, if you convert them to CMYK, they you might be changing the color unexpectedly by moving it into a CMYK gamut. Next, there's the issue of reproducing the file and making sure that the CMYK colorspace of the new "spot" if properly recognized and then transformed into your final colorspace. Using Lab skips that part because the color gets to live outside of a colorspace. That way, when you really late-bind, you have a good chance of mapping the spot into the best possible version of that color in your final output condition. In terms of "alternate colorspace", hopefully that's code for: "don't mess with the spot". When exporting to file, you can choose either "map to CMYK" or "keep as spot". If you plan on actually printing the file using spot inks.... or are unsure of the print-condition/colorspace when it will be printed... I would define your colors in Lab and leave them as spot when you export to PDF. Make sure that's clear in your rule set. If you somehow know you are printing in a particular CMYK condition and need to createa CMYK-only file, then you would use a different rule to convert your spots to CMYK. For example.... maybe you are going to print the file in CMYK-only on an offset commercial press (or a digital device that is simulating one). In that kind of scenario, converting to CMYK makes sense. Hope that helps. -Marc L -GMG Message: 1 Date: Thu, 9 Jun 2022 14:03:34 +0000 From: Axel Robert <axel.robert@ubisoft.com> To: "colorsync-users@lists.apple.com" <colorsync-users@lists.apple.com> Subject: Spot Colors | Alternate Color Space behaviour | PDF export. Message-ID: <EE772B4C-D403-4519-9407-9B41DBDC70D9@contoso.com> Content-Type: text/plain; charset="utf-8" Good afternoon. I was wondering if somebody else already experienced and solved this problem, as well. We built, dedicated to creative agencies, a specific color settings and pdf export couple for certain production files in which we manage ourselves the RGB to CMYK conversion. It?s almost a late binding workflow before sending the final PDF to our printers. So, all raster images remain in a specific RGB color space while Benday and vectors are still in CMYK. So far, we did have any issue, but we recently received a document with a Spot Color template in it. And when we checked it, it appeared it had been tagged on the Alternate Color Space with an ICC profile (no more specific indication). We tried to find why without any success. But we also experienced the same after many tests in In Design and Illustrator by creating a simple vector shape to which we added a Spot Color from the latest Pantone library. The PDF export has no color conversion except an OI and OC for the PDF itself. And despite all the color swatches we use, the result is equal. The only difference lies when we use a PDF Export Preset which converts colors to the destination. In such a way, the Spot Color uses the CMYK mode as by default Alternate Color Space. How is it possible? Would you have any idea? Thanks! Axel UBISOFT | Axel ROBERT |Senior Manager, Prepress & Quality Ubisoft encourages work/life balance and embraces flexibility. My workday may look different than your workday. I have sent this message at a time that suits my work pattern, but it is not my expectation that you read, respond or follow up on this email outside your working hours.