Each milk painted piece is protected with either beeswax or hemp oil. These are both natural and incredibly durable, but they are NOT plastic, glass or melamine for example. Those are non-porous surfaces that are unaffected by moisture and, in most cases, heat.

 

Both the wax and hemp oil cure over time. For wax it takes around 30 days for it to fully cure. Your piece may not have reached full cure time so best to limit its use for 3 weeks. (Avoid placing heavy objects on it or anything that might scratch the surface.) Once cured, the surface will stand up to normal use but, like any wood, it can be damaged by moisture and heat. For painted furniture treated with hemp oil, the oil is a 'drying oil' and that means also ensuring it's had its time to cure. Hemp oil protects while maintaining a beautiful and breathable finish that won't yellow or crack like many synthetic poly urethanes or varnishes can.