Roy,

Great question! If you get an answer please share it with me as I am curious about the same thing.

I have been collecting these UV varieties for some time now. Since I didn't have a good way of photographing the UV markings I have been putting the chips in a box and they have been building up. I finally found an easy way to make the pictures, so I have been working on that box of chips lately. I only have a few chips left to go!

Greg