Hi, mxshiki.
What I said before is right. I generated artwork as JPG and PNG, imported into Krita and converted to color profile of my ink and sublimation printer. Then I exported it in JPG with the same color profile embedded. So I imported these corrected arts into Scribus keeping the sublimation color profile. I corrected their size and position on the A4 sheet and exported them as PDF, with the Screen/Web option (since my sublimation icc profile is RGB) and maintaining the embedded profile of the images. Finally, I did the printing using Adobe Acrobat Reader (I was on Windows), following guidelines for sublimation. In Acrobat Reader there is no difference in the image converted as a sublimation color profile. Now I'm going to test on Ubuntu, using the Master PDF Editor, because in addition to preferring Linux, the Master PDF Editor clearly shows the images that are converted.