it is difficult to figure out the difference among the brush presets. Most of them, look quite similar (yeah, I am not an artist...) :-( Maybe, it might be useful to add, for instance, a caption under them (e.g. charcoal, watercolor, spray and so on).
*** Bug 310320 has been marked as a duplicate of this bug. ***
This has been fixed in commit 2803e28b27fe2c2ba977b02ee0da71cd91ca69d0 - experimented with a few options, this seems to work. Feedback welcome.