If you're noticing small dots on your finished product, this is likely due to excess moisture. We recommend pre-pressing most substrates (cups coating) to ensure you get all of the moisture out. To do this, just place your sublimation tumbler inside your oven (without the paper) and let the tumbler bake for about 40 seconds to 1 minute. Then, let the substrate and cup cool down, place your transfer paper on, and continue sublimating like normal. If you are using a press, make sure to wrap your tumbler in parchment paper before pre-pressing it. This should fix the issue of seeing small dots on your cup.