OK all you PINTERESTers! I have been reading all the PINS about writing on mugs with sharpie markers and heating them in the oven... so I pulled out all of my markers and experimented.
First try was to use a regular black sharpie, let it dry, then following all the PINTEREST post instructions I heated it at 350 degrees for 30 minutes. Although it looked wonderful going in and coming out... if you used a scrubby sponge to wash it, the writing came off.
Next I grabbed an OIL BASED SHARPIE marker (purchased at Michael's)... and wrote on the mug. The ink flowed easily, the pen a dream to hold. Mistakes could be removed with a dab of nail polish remover on a paper towel. I let the mug dry over night and even though the writing stayed put when I scrubbed it... I baked it in the oven for extra insurance.
Lastly I tried a DecoArt Glass Marker (also available at Michael's) which are specifically designed to write on glass, porcelain, and ceramics. The directions read to let it dry for at least 8 hours then put in a cold oven, heat up to 375 degrees, bake for 45 minutes, turn oven off and let sit until cool... Then remove it. BTW I followed the same directions for the Oil Based Sharpie mug above. The paint seemed to drag as I used the pen and wasn't near as smooth as the Oil Based Sharpie. Although the finished project had a bit of a raised surface. The writing is permanent and didn't budge when I tried to scrub it off. I didn't try to remove mistakes so I am not sure the nail polish remover trick works with this, but I don't see any reason why it wouldn't.
So... bottom line??? In the future I would recommend the Sharpie Oil Based Marker. I felt the ink flowed smoothly and gave a darker and thicker line.
GOOD LUCK! Let me know if you make anything with this technique... or if you have any other 'helpful hints'.