It depends on whether the sticker is waterproof. More precisely, it depends on the material used for the sticker. For example, stickers based on paper or card paper are usually not waterproof, although they can be made waterproof by adding plastic laminates or similar waterproof coatings. For example, the UV coating on the card can increase waterproofness on the applied side. Stickers using adhesives dissolved or degraded in water can not be considered waterproof either. Similarly, stickers using water-soluble inks and pigments cannot be considered waterproof.
In order to make the stickers waterproof in real sense, the materials, adhesives and inks used must be able to soak for a long time. Vinyl and BOPP (biaxially oriented polypropylene) are the two most commonly used materials for waterproof stickers. Waterproof adhesives are also commonly used in paster materials made from vinyl and BOPP. Professional printers also usually use appropriate waterproof ink. However, considering the differences between different sticker manufacturers, it is not possible to determine whether the sticker has waterproof function before testing.
The easiest way to test waterproofing is to order stickers or stock samples from a sticker printer. Many online printers, including UPrinting, offer free stock samples that can easily test waterproofing or any other use.
Not all stickers are waterproof. To make stickers waterproof, you need the right combination of paper, adhesives and ink. It's also important to know where to use real waterproof stickers. The material used in the sticker will let you know whether it is waterproof or only waterproof, but the only sure way is to order samples for self-testing.