I had bought some powder paint from Bass Pro Shops (watermelon flake) once.... Got home and opened it up and it should have been named Funky Chunky!!!! Talk about boulders of paint 'rocks'!! I tried everything.... crushing it, smashing it, cursing it ... but each time I'd put it back into the bottle it would just clump right up again!! Finally had it sent back to BPS and got it replaced. Now I'm sure to open up the bottle to make sure it's nice and fine! But by all means... keep it away from moisture!!