Many factors play a part in why your sublimation paper may be sticking to your cup after you take it out of the oven. Heat is a part of it because if the cup is baked for too long, the paint softens causing the paper to stick. Also, if you remove the paper while the cup is hot, you have less of a chance for the paper not to stick. Lastly, if using a press, pressure will also play a factor in this as well as time and temperature. If your paper is stuck to the cup, make sure to use water to try to remove it. Sometimes the paper will come right off when water is applied.