VEVOR Sublimation Oven Machine, 13 Qt, Fits 20oz Tumblers, with 1 Heat Air Gun, 50 Shrink Films, 1 Tape and 2 Heat Gloves, Oven for Sublimation Blank Tumblers, Mugs, Bowls, Off-White

Based on the technical specs of the VEVOR 13-Quart Sublimation Oven (which operates at 1600W to 1700W), it typically takes about 5 to 8 minutes to preheat to a temperature over $300^\circ\text{F}$ ($149^\circ\text{C}$).

Baking polymer clay and polymer clay is fine, but other types are not recommended as the required temperature may not be reached.