OK, so there are type 4 (UV plus vis light) and type 5 (UV only) sun optical mice.

Type 4 mice require a different optical pad than type 5. Type 4 mice are tricky because they have to be adjusted to the grid (parallel vs perpendicular) in order to work correctly. There is a ps file that prints the type 4 mouse pad grid on paper. Do I have to laminate that print, or print it on a transparency and glue that onto an aluminum foil or print it onto a reflective foil? Because my printed pad on plain paper don't work with type 4 mice. Sniff. I wonder why I find so many optical mice in the garbage here.