What do you call those pictures that change when you look at them from different angles?
I'm trying to think of what the technology or trade name is of those pictures that change when you turn them. Sports cards used to have them and were called Sportflix. They're very fine rows that only allow sight of the picture at specific angles, so when you change the angle, you get a different picture.
I have some collectibles pins I'm going to try to sell on ebay, but I'm not sure how to title them.