I was walking past a hospital this morning, and I noticed signs all along their boundary wall that said “Warning: Anti-Climb Paint”. There was a lighter band of paint up to about two feet off the ground, and then another light band at about waist height, roughly one brick wide. The colour of the paint was reddish/terracotta. I reached out and touched it, but it didn’t feel any different from the other paint; certainly not more slippery or anything like that.
Obviously they weren’t entirely convinced of it’s effectiveness, because they had barbed wire on top, but what is this stuff? How does it stop people from climbing the wall?
Hmm. They use anti-climb paint on some railings round where I live, and it definitely is slippery - feels quite oily, in fact. (Also feels nasty when you get it on your hands.) Perhaps the stuff on your wall is just a bad batch?
Anti-climb paint is usually some kind of non-drying, sticky, slippery, oily black goop*; it may well be that you weren’t even looking at the part that was painted with it, since it is most often put on the tops of walls and roof edges, rather than vertical surfaces where it might eventually run and drip. It is nearly always put out of normal reach too, so that the only way to come into contact with it is if you’re doing something you shouldn’t be.
*It has several purposes:
-To make climbing impossible (slippery, oily)
-To make climbing unpleasant (sticky)
-To indelibly mark the clothes and body of a person attempting to climb (black goop)