I was bored and annoyed with all the requests for 'dotted brushes' in all my brush communities, so I decided to make a tutorial on how to make them yourself. It's very easy, but if I've confused anyone, feel free to tell me. =) This, as are all my tutorials, is for Photoshop.
Open your brushes menu. This is NOT what I mean. If you don't know how, go to the Window tab and click brushes.
And now, this menu should appear on the right side of the screen:
As you can tell by my neat little circle, we're going to be messing with the 'spacing' option. Play with the arrow and see what results.
And here's what results:
So now you can go forth and sign a lot of dotted lines...or something. Hope it helped!