> OK, it looks like the info I need isn't out there.
> Can someone point me to the relevant files in the MAME source tree, that deal with
> LAY file parsing and artwork rendering, please?
Those are older posts... but I think that's what you're asking, right?
And then look at some of the "Other Artwork" to see examples using masks.
RELAX and just have fun. Remember, it's all about the games.