beautiful work, can you explain how you proceed for the line art (type of brush, etc) please ?

It's like a rough chalk brush that I use very small (7px wide) it gives this look that breaks up the line a little bit.

I talk a bit about the brush here http://www.bugglefug.com/?p=112#comments

I do a rough sketch with a palette knife style brush, then I just draw the lines on a layer above that (lowering the opacity of the sketch before) nothing fancy.

What else do you want to know?

sorry for answering three months later... Thanks a lot for the tutorial !