@denzjos, Come on, no need to go to gimpchat 
that script here: https://www.gimp-forum.net/attachment.php?aid=2116 and of course should always mention Ofnuts plugin ofn-path-to-shape.py from http://sourceforge.net/projects/gimp-pat...s/scripts/ (ofn-path-to-shape.zip dated 2016-12-26)
@hedrickbez Is that brush a full circle shape ? Without using it not easy to see what is going wrong. Sometimes a brush is used as a 'stamp' one-click to paint, sometimes a brush is used with the eraser tool to cut out a shape.
Another way is use a path, I will attach one I made It is sized for your 1000x1000 image but a path (a vector) scales up or down without loss of quality.
This one milled-edge.svg is not opened as an image, right click in the paths dock and use import path. Then Select > from Path, and in this case invert the selection and cut out the edge.
50 second demo: https://i.imgur.com/sncNdE8.mp4 (should be there but imgur is a little flakey at time of posting)
that script here: https://www.gimp-forum.net/attachment.php?aid=2116 and of course should always mention Ofnuts plugin ofn-path-to-shape.py from http://sourceforge.net/projects/gimp-pat...s/scripts/ (ofn-path-to-shape.zip dated 2016-12-26)@hedrickbez Is that brush a full circle shape ? Without using it not easy to see what is going wrong. Sometimes a brush is used as a 'stamp' one-click to paint, sometimes a brush is used with the eraser tool to cut out a shape.
Another way is use a path, I will attach one I made It is sized for your 1000x1000 image but a path (a vector) scales up or down without loss of quality.
This one milled-edge.svg is not opened as an image, right click in the paths dock and use import path. Then Select > from Path, and in this case invert the selection and cut out the edge.
50 second demo: https://i.imgur.com/sncNdE8.mp4 (should be there but imgur is a little flakey at time of posting)