2D picture with relief: how to select deep ends?

[denzjos]

The sign is not symmetrical but I made a rough sketch with paths anyway. Use 'Script-Fu / Shape Paths / Circle (Polygon, Star)'. You can further finish the paths (cut out pieces and add lines). Finally, you can apply a neon effect to the paths. To make the paths fit with the sketch, use 'Tools / Transform Tools' and untick 'aspect ratio' and 'around center'

  sign.xcf (Size: 1.16 MB / Downloads: 140)