Muggles are the WORST. Don't let them get you down. Caffeine will help with that. Our vintage reproduction enamel mugs are made from thick enamel-coated steel. They are heavy (for enamel mugs--still lighter than ceramic), smooth, wonderful to drink from, and crazy sturdy. Dishwasher safe. These are steel under the enamel. So please don't use them in the microwave.