I've been using the price sticker dots from Staples for pricing my bowls, but I've noticed that if the sticker is left on the bowl for more than a couple of weeks it leaves a sticky residue. I don't want to have to use a goo remover to clean this up as it would probably leave a mark in the finish, and it's a pain to have to remove then re-sticker everything between each show. What's everyone using to mark prices?