Loreal root touch up

[HowlingAtTheM00n]

Does this stuff dry ? Or would it rub off?
I have some hair thinning on the front due to medical condition and wondering if I could use this to cover it but don't want something that's going to rub off easy.
Is it waterproof

I use it everyday. It doesn't rub off. I have been caught out in the rain and it hasn't run off and it does need a good scrub in the shower to remove it. I find it excellent, though it does feel a little bit dirty if you run your fingers through your hair.