There are a few things you need to consider when choosing a tumbler for sublimation. The most important factor is the size of the tumbler. It needs to be large enough to fit the image you want to print. You also need to make sure that it is made of a material that can be sublimated. Glass and ceramic tumblers are not ideal because they can shatter when heated. Polypropylene and polyethylene tumblers are good choices because they can withstand the heat without breaking. You also need to make sure that the lid fits tightly so that the heat can properly penetrate the tumbler.