im usin a Hansa - system.
and meteora is right specially with, aftery time usin cleaning it!
and take tha doubble one.
thats the diff. 2 cans,also a lot of work after u finished ur pix,...
i havent bought diff. caps,. but im goin 4 new this sommer,..
i cuted 1 paper in diff curved lines and combined this sometimes with a normal pencil.
if ur working on 4 xsampl on motorcycles u use a masking foil.
4 this stuff are online guides, maybe i post up a beginners guide with some pic,.. but 370km between me and my stuff is a good xcuse, that i take little bit longer,..
and the end its like writtin, practicin, practicin.... uŽll luv it
peace