This blend includes a single brush that references the 8 image textures with alpha that I made in blender 2.77 with the procedural masks and brush textures. The 8 images are loaded as a brush mask image sequence, and if you press Alt-A or press Play on the timeline, you will be automatically cycled through the brushes on each dab or stroke. You can still choose any color you want from the color picker or your palette, and it will use that depending on your mix mode. The zip file contains the blend and a base image in the 3d view to paint with, and the 8 image textures. I hope you have some fun, and these seem to be good for regualr grunge effects when using pressure, as well as good for a watercolor type effect.
I hope description/explanation comes in zip file. It looks great. Might be become built-in feature.
So useful, thank you!
Cheers, Rex