CS4 Masking overlapping layers

Hello friends.

I've made a flexible armature man with the bone tool and I want to be able to mask it with flat black to make him into a sillhouette, but some of the parts where pieces of armature overlap (eg where the thighs overlap with the hips) become seethrough.

Some overlapping parts dont have that problem though, so I think there must be some way to fix it?!

If anyone can help, or suggest a better way, I'd be most grateful. Thank you.

-bones

ps. any suggestions how/whether to upload a small example flash document would be appreciated too.