It is all in making a decent mask, then a bit of bump-mapping.
However for the stripes there is symmetry painting, one of the options is tiling. All it takes is one diagonal brush stroke.
Going back a bit, another example https://www.gimp-forum.net/Thread-Image-...21#pid6521
However for the stripes there is symmetry painting, one of the options is tiling. All it takes is one diagonal brush stroke.
Going back a bit, another example https://www.gimp-forum.net/Thread-Image-...21#pid6521