These were for my mom for Christmas. I remember seeing a couple hand painted glasses at her house, I believe they were of astrology signs. She loved these glasses but her man put them in the dishwasher and the paint started peeling. Noted.
use enamel paint. (I have tried the whole Sharpie on ceramic thing that Pinterest makes look so easy but it NEVER turns out for me)
Bake in the oven (upside down) at 350* for 30min OR let air dry for 21 days.