After using vinyl flips for years, I've decided to move my collection to cardboard flips. I bought the type that are not self-adhesive, but don't want to use staples to hold them closed. Instead, I'd like to use sort of white paper sticker. I just put a bunch together using some Avery #05412 labels that are 5/16" by 1/2". An example is shown below.

The problem is that after a day or so, some of the stickers come unstuck. I don't like the idea of hand cutting my own size of sticker, but I also don't want to buy another package of slightly larger stickers and find they do the same thing. I'd be interested in hearing what other collectors have used to hold their flips closed.