Because of the number of different heat press machines available, it can be difficult to pinpoint accurate pressure. Some heat presses offer a digital readout for pressure adjustment, some only a manual crank. But, most transfer suppliers will recommend application with light, medium, or firm pressure.
Light pressure is usually between 25-30 psi if you’re using an automatic heat press. If you’re working with a manual heat press, light pressure means the upper platen will be easy to close with just one hand. Medium pressure is usually between 32-38 psi if you’re using an automatic heat press. If you’re working with a manual heat press, medium pressure means the upper platen takes some effort to close. Typically, you can close it with two hands and some effort. Firm pressure is usually 40 psi or higher if you’re using an automatic heat press. If you’re working with a manual heat press, firm pressure means the upper platen is difficult to close with two hands and a lot of muscle.
—Howard Custom Transfers
