Hydrochromic Water Re-Active Reveal Color Changing Ink Paint (4oz)

I've tried a bunch of hydrochromic paints and they're all kinda like this one. It's a fun idea in theory -- a paint that goes on white when dry and turns clear when wet, so you can reveal something fun on your shower tile or umbrella or sidewalk.But... it doesn't work great. It takes a pretty thick set of coats to actually hide (when dry) what's underneath, and that makes it prone to cracking, and also not entirely transparent (more like translucent) when wet. It's hard to get the thickness just right. Mixing some pigment into the hydrochromic helps a bit but adds a tint when wet. And even aside from all that it's not very durable paint, it's kind of powdery and scratches off. And you can't add a top-coat, otherwise the water won't get to it.You *can* make it work, we *did* make it work for a puzzle application (invitation cards that reveal a secret design when wet) but I'd prefer not to use it again.