Looks interesting thanks guys!

Mark, I think yours would take up less memory if you worked in pixels, it looks like you're playing with twips which would leave a lot of unused array sections, I was thinking about an array of UDT, you could look up the x and y with a binary search algorithm and take almost no time to find what object you're in.

I'll need to do a bit more study on Kedaman's idea though, looks good but I've never used that sort of code before.

still, I'm not planning on working with anything animated so I should be ok.

Paul