El Grande Style Large Ceramic Coffee Mug With Big Handle, Black 15 oz. (Pack of 2) Dishwasher safe, microwave safe. Feeling crafty, Can draw on the mug with an oil based Sharpie paint-pen and Preheat your oven to 350 degrees. Once your oven is heated, set your mugs inside and let them bake for 30 minutes. After 30 minutes, turn off the oven, let the mugs and oven cool down and now you have for Graduation, Birthday, Holidays, Anniversary and much more