Removable Sticker Set for Gloomhaven - Rules of Play says:

A removable replacement for the stickers contained in Gloomhaven. It includes all the location, enhancement, and achievement stickers, plus seals for envelopes & boxes, and the lock for the Town Records book. Made from durable vinyl with a non-transferring adhesive, these stickers can be removed from the board and cards without tearing or leaving residue.