Our 12 oz vintage reproduction enamel mugs are made from a thick enamel-coated steel. They are heavy (for enamel mugs-- still lighter than ceramic), smooth, wonderful to drink from, and crazy sturdy. You can abuse the heck out of them.
Each mug is individually printed in our Seattle studio, and made with love and care... and a small hope of offending at least one person who sees it.
Toss these into a bag to take on a picnic, or take camping and abuse liberally. They're good for sneaky cups of wine or whiskey wherever you happen to be.
MICROWAVE & DISHWASHER USE:
These are steel under enamel. So please don't use them in the microwave unless you want to create a localized lightning storm in your kitchen and pretend you're Harry Potter. Or Voldemort.
They are dishwasher safe and won't fade... though keep in mind that metal does rust, so any chips in the enamel will allow the steel underneath to rust if you put it in the dishwasher. But in general... dishwashing should be fine.