lulu, I didn't use bill's edge-blend shader.  to do this in photoshop is somewhat counter-intuitive
and complex (e.g. the initial edge-blend render has no lines anywhere, one has to be familiar
with high-pass filter and level adjustment in photoshop), but it satisfies the cartoonist's desire
to have the linework in a separate layer.  that's why i would recommend either bill's or olivier's
shader instead.