Polycarbonate can be printed on both heated and unheated build plates, but it is recommended to use a heated plate if possible. This helps to prevent the filament from warping or curling as it cools, which can lead to poor print quality. In addition, using a heated plate can help to achieve a higher level of detail in the final print. As a result, it is generally advisable to use a heated plate when printing with polycarbonate.