Like pattern... Jezz now you made me open my Photoshop... well first make new layer i this top of my head... If you want to make pattern like a scaline style make it small... like 3x3 4x4 i donno something like that... Now you erase everything on that new thing you got.
Ok here
Open photoshop
File -> New -> Then make it small like 3x3 pixel.
Ctrl + all the way (it makes you zoom in if you didnt know

)
Magic Erasier *Click!* ( Now everything is gone...)
White 1 pixel pencil. *dot dot dot* ( make it the pattern you want it to be. )
Edit -> Define Pattern (this was the part i didnt know off my head XD )
Is this what you wanted... Im pretty sure define brush is almost the same way but bigger...
To use pattern
OMFG you said shape..
here herei learned shape from this site.. i usally book mark a lot of stuff like new stuff i learn lol hahah XD
http://biorust.com/index.php?page=tutorial_detail&tutid=48