I'm trying to render a scene in a size big enough to practice some postwork, hair painting and such. At first I had it too small, so when I painted with a one pixel brush, it looked like I was painting with a lincoln log. Then someone suggested I render it really big to paint on and then resize. I tried to do 4000 x3000 at 72 dpi. It came out all pixely - if that's a word. Anyway it looked like the very dickens.. so my question is this. What Is a good size and resolution for rendering with post work in mind.

thanks,
myst