Sharpie Mug Project I've read a lot of different reports on this so I did a test run of random doodles before making anything I actually cared about. Used Oil-Based sharpies Let dry 24 hours Baked at 375 letting plate warm and cool with oven. Washed in dishwasher on high setting. Reviews: The colors change. Test each before making your project. How did blue turn pastel green? Everything except silver stayed on. If must use silver possibly hand wash?