Post-it’s Extreme notes can go a lot of places regular Post-its can’t. They’ll stick to rough surfaces like wood and brick, and somehow, they’re even waterproof. We blasted them with a kitchen sink last year, and the paper never shredded, and the ink never ran.
source https://kinjadeals.theinventory.com/post-its-extra-sticky-water-resistant-extreme-notes-ha-1829571400