Screenshots of what you're doing.

That is possible.. I can also provide an alpha map if you need any, would come in handy.

Yes that would be great .. I still need to figure out how alpha masks can be applied in Cairo, but I'm sure it's possible.

EDIT: On the other hand, doesn't PNG support 8bit alphas masks already? So if you give me a transparent PNG, I shouldn't need anything else, right?

Yeah it does, I just mentioned it in case it would come in handy, I could provide it then

Though... an example: if I'm going to round the corners, and give you an overlay of a border with rounded corners, you'd also need the alpha map for the background, or else the background's pointy corners will stick through the overlay border, understand my point?