I want to make some decorated mugs and as you are probably aware there are a lot of blogs that talk about decorating mugs with Sharpie markers. Well here is my test and I hope it saves you from the heartache of having your art work wash right off the mug. I would not use a regular Sharpie marker for this project no matter how many you have seen on the web, the artwork will not last. Black will hold up for a time with hand washing, but in time and use it will fade away. The Sharpie paint markers will work, I think it best if the mug was hand washed, but it does stay on for a time in the dishwasher. Again in time it will fade or come off if washed in the dishwasher. These markers cost about $13 for 5 markers. Dark colors work better than light colors. The best and longest lasting is Pebeo Vitrea 160 glass paint or marker. Markers cost about $5 each and the paint is about $7. Not cheap, but long-lasting.
I pulled out a small pitcher I had in the cupboard. Test 1 is the regular permanent Sharpie marker. Test 2 is the Sharpie paint markers and test 5 is the Pebeo paint. I let the cup rest for 24 hours after painting then fired in the oven at 325 degrees for 40 minutes. Setting in the oven as it comes to temperature, cooking at 325 degrees for 40 minutes and leaving in oven until it is back to room temperature. First washing was by hand. The blue, gold washed right off, the red faded a lot and the black did pretty well. Then I sent it through the dishwasher twice. Sharpie paint markers still did pretty well, there was some fading. The metallic gold is starting to come off. The Pebeo paint show no difference.
I hope this helps for those of you who want to do a mug.