I've often wished there was a variant of Post-it Notes that was durable enough to use outdoors or in the shop. Out here in the country I've worked on timber framing projects, gates, fences, sheds, coops, windowsill repairs, etc. where labeling parts would've come in handy (i.e "Do NOT cut the mortise on this face") but writing on them was impossible or impractical.
Turns out, they do exist. 3M has created Post-It Extreme Notes that are water-resistant and "feature 100X the holding power, yet remove cleanly." They'll stick to brick, metal, wood and can be rained or snowed on--but the catch is that you can't affix them to things that are already wet, which makes sense. The usage cases look pretty darn compelling:
Prices on Amazon run about 11 bucks for 12 pads that have 45 sheets each.