(03-16-2023, 04:18 PM)Galnart Wrote: ..snip...
I doesn't seem to be that bad with grid distance 40, what is the best setting?
Make the Grid a proper fraction of the canvas size. The default is 30. For a 500x500 canvas 50 is good. For a 400x400 canvas 40 is good.
this example 500x500
But from the subject title - symmetry you might be better without an out-dated tool like gfig and use the Gimp 2.10 symmetry tool. https://docs.gimp.org/en/gimp-symmetry-dialog.html