I tried to ctrl mask with a rectangular alpha. I could get rid of the fuzzy fall off of the brush, but I found no way to get rid of the circular brush pattern to favor my rectangular alpha I try to paint on. How can I change to a rectangular alpha brush?
Lemo
I think its brush 28.
I have not found a way around the problem, or square it either. There’s another post on the topic here: Alpha Fading ZB3
It looks like Kris Kosta’stexturing technique doesn’t work anymore either, the one where you use the plane to feathered with an alpha to texture with.
I think its alpha brush 28.
Yeah its a smaller rectangle so it fits inside the mask/circle when its drawn and the corners arent faded out by it so much (but they still are a bit) 
You can reduce the fade further by setting the Alpha Adjust curve Focal Shift to 99.
I loaded my own alpha which is rectangular. And that’s projected though a circle, thus cutting the corners of. I guess I have to do the usual ZB dance and make a mask with a circle, and then fiddle my mask into that circle and then load that messed up alpha which then will look alright because the corners are cut off. GAH. Tiny ZB3 issue #23454223 
Lemo
Lemmo, using alpha 28 should help, but if the alpha is too blurred for you, perhaps this could help. This is crisp PSD file for loading in the alpha import thingy.
Default, Bush 28, and 28 alternate:
Hey, lemmo, we posted at the exact same moment! LOL 
look at my post above. Your problem is that your rectangle needs a buffer zone on the sides so it doesn’t get cut off thru the faded circle thing.