My brother showed me the illustrator way that I don't really remember but in photoshop you put a gradiant on and then go to filters>pixelate> color halftone and then a window will pop up asking what diameters and how far apart you want the dots to be things like that you can change them to whatever you want then click ok. Then the layer you have the gradiant on change to exclusion or difference one of those I think or you can just experiment with the other effects There you go hope that helped
LOL! I would've picked up a brush that did it my self It's interesting to see how peoples do it that way sounds about right though. You sound like you've got a computer geek as a brother like me Listen to him- if he's like mine, then he's got alot of tips he can give you ^^
Yeah if I never asked him about it I probably would've done it by hand too My brother is a bit of a computer whiz when it comes to photoshop, illustrator, and corel. He's handy to have around lol