These sticker sheets are made of paper with a plastic coating, they'll last longer if not exposed to water.
Please note for the "Gem Friends" sticker sheet there was a manufacturer error where the Lapis Lazuli head sticker was not cut out. You'd have to cut it out manually if you want to use it!
★Size Dimensions★
Approximately A6 sized
105 x 148 mm 4.1 x 5.8 in
Note that the size may have slight variations because of the production process