Toon Material, add edge highlights with Opacity Map?

[cadjockey]

Hi

I'm loving the toon materials but is there any way of using say the hard pen outline material to generate outlines where I have an opacity map to cut holes in the base material?  eg. imagine a metal grille with holes punched out using the opacity map, I'd really like to see the edges of the holes when using a toon material but it seems not possible without modeling them in fully?

Rich