Jed,
I suspect the vinyl sheets are "magic" stickers like those pizza ads and else that are to be stuck on a fridge door. They contain periodic poles NSNSNS... so not very good for counting pulses. Just take such a sticker and cut off a strip, use the end of the strip to go around the rest of the sticker, the strip end jumps up and down to indicate periodic poles. A physics professor once showed this in a seminar I attended, pretty cool trick.