This is a followup question to gimp: Background removal gives gray fringe, when exported as pdf:
To reproduce the problem you have to follow these five steps:
- In GIMP, create a New Fileo with Advanced Options → Color space: RGB color and Fill with: Background color (should be white to see the problem).
- Add an alpha channel to your background.
Take the Free Select Tool and select an arbitrary area of the picture like this:
Press delete and you will end up with something like this:
Choose File → Export as... → PDF and open it in your PDF viewer. You will end up with this:
Why does this gray line appear? How can I get rid of it without flattening the image? Note that the gray line also appears, when first exporting the image as PNG and converting it to PDF afterwards. It seems as if the different exporting options have no effect on the outcome.