We are very proud of this easy to clean melamine mug. Not only does it come in a pattern that mama will enjoy, the top is easy and fast to push onto the mug and stays sealed! We have tested this cup for over a year at home, and despite many dishwasher cycles, the cup's seal has stayed perfectly tight, no leaking except through the small drinking holes where liquid should come out. The design will withstand the dishwasher and stay bright and cheery too! The search for a sippy cup that stays sealed frustrated us, and cool patterns that us mamas liked too seemed non-existent. Helmsie's sippy cups check both those boxes, and will be the perfect gift for kids (and mamas). Sippy cup is 100% melamine. BPA free.