(10-20-2022, 08:53 AM)rich2005 Wrote: If the painted line is dark on a lighter background it is possible to shrink using Filters -> Generic -> Dilate It does not work with a transparent background and repeated use will degrade the line(s)
Another option to Dilate / Erode, can be, Filters > Distorts > Value propagate...
It does what "Dilate" and "Erode" do, but has options in it, and Alpha channel is handled by this filter.
40 seconds video
https://imgur.com/MQ7Lkcl