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CMYK issue: Krita or Cyan
#14
Random thoughts:
I've achieved very good RGB to CMYK conversions for printers using Cyan, as a stand-alone application, in version 1.2.4, not as a GIMP plugin. From an example:
  •  Approximately 76% difference between the original RGB and a CMYK *.tiff if I use the Fogra39 color profile.
  •  Approximately 56% difference between the original RGB and a CMYK *.tiff if I use US Web SWOP v2.
Quite correct percentages, considering we're using different color modes and one image is intended for screens and the other for paper.

The only way I've achieved an unacceptable 99.9% difference between the original RGB and the CMYK tiff is when I use the direct export provided by GIMP 3.0 (without a plug-in). When I open the file in other programs, the tonal differences are quite large. But CURIOUS!: When I open the converted image in GIMP, whether or not you enable soft-proof, it looks great. As if GIMP had done its job well, but the other programs don't recognize it. I don't know why this happens.

Although Fogra emphasizes offset, I prefer Fogra39 over US Web SWOP v2 because it offers far fewer out-of-gamut colors. This can be confirmed within GIMP or Scribus. It also depends on your needs.

Within open source software, another great option for creating a PDF for printing is to use Scribus to generate a full CMYK:
  •   Export as PDF/X1-a (if there are no gradients and/or transparencies).
  •   Export as PDF 1.4, 1.5, or 1.6, enabling Color Management, choosing Printer (Color tab), and if bleed marks or crop marks are not needed.
In both cases, all images will automatically be converted to CMYK.
  • If you are going to export as PDF/X-4, it forces you to convert RGB images to CMYK beforehand (with Cyan stand-alone, for example)
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Messages In This Thread
CMYK issue: Krita or Cyan - by enrimoore - 01-04-2025, 11:27 AM
RE: CMYK issue: Krita or Cyan - by rich2005 - 01-04-2025, 01:39 PM
RE: CMYK issue: Krita or Cyan - by enrimoore - 01-04-2025, 02:50 PM
RE: CMYK issue: Krita or Cyan - by rich2005 - 01-04-2025, 06:05 PM
RE: CMYK issue: Krita or Cyan - by enrimoore - 01-04-2025, 07:22 PM
RE: CMYK issue: Krita or Cyan - by rich2005 - 01-04-2025, 08:32 PM
RE: CMYK issue: Krita or Cyan - by enrimoore - 01-05-2025, 12:19 PM
RE: CMYK issue: Krita or Cyan - by rich2005 - 01-05-2025, 12:50 PM
RE: CMYK issue: Krita or Cyan - by enrimoore - 01-05-2025, 02:24 PM
RE: CMYK issue: Krita or Cyan - by rich2005 - 01-05-2025, 04:40 PM
RE: CMYK issue: Krita or Cyan - by enrimoore - 01-05-2025, 06:27 PM
RE: CMYK issue: Krita or Cyan - by rich2005 - 01-05-2025, 06:54 PM
RE: CMYK issue: Krita or Cyan - by enrimoore - 01-05-2025, 08:23 PM
RE: CMYK issue: Krita or Cyan - by Dark Allure - 04-22-2025, 05:17 PM
RE: CMYK issue: Krita or Cyan - by Dark Allure - 04-23-2025, 08:02 PM

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