I would put a piece of wax paper in between them. That should keep them from sticking together.

Hope this helps.

I would take a board and pound some little finishing nails slightly into it, about 1-3" apart, all over, and lay them on top of the nail heads so air can circulate around them, letting them cure. Try to get them all about the same height.

I hate when painted things stick together, it always pulls the paint off when you break them apart.