I am looking to decorate some coffee mugs with a permanent marker. People have tried this before and attempted many different techniques for keeping the dried ink on the mug. http://www.craftaholicsanonymous.net/21-tips-for-diy-sharpie-marker-mugs The most common technique involves letting the mug set for 48 hours before firing it in the oven. I suppose this allows enough time for all of the organic solvent to evaporate before firing it. Is the firing temperature of 350F-450F actually enough to melt the ink into the glaze?