Anon10/03/25, 13:51No.2948517
Water based paints have rheological additives you can add, but the average person isn't going to have them. Something like Acrysol TT-935 will get most paint THICC with just a small amount. But that's only for water based paints. Many thickeners in paints are pH activated, so you can sometimes increase the thickness if you add some ammonia, although I've never tried doing it with household ammonia concentrations...
Solvent based paint you're kind of screwed if you go too thin. We used to just agitate the tanks to try and burn off the solvent, and that works a little bit but it takes forever.