Any chance you could include a raw image version of the brushes? For me at least the .abr version used is too recent to be recognize by gimp, resulting in black square brushes there.
Viewing post in Glitch Pixel Brushes II comments
Sorry, ive been dealing with life events and other stuff atm and haven't gotten around to this. The brushes themselves are just a single square that paints a pattern w. a transparent bg down, however your converting them is probably converting the actual brush shape but not the pattern that goes with it is what im imagining.
while i think that might also be doable with any plain square pixel brush, that's really cool and i never thought of that :O
i'll have to keep looking into a way to get these brushes to work the way they're "supposed" to because i'm still interested in seeing them in action, but this technique opens up a lot of stuff to me :D thank you!!