In one example in accordance with the present disclosure, a printing device is described. The printing device includes a single thermal printhead that includes an array of heating elements. The array of heating elements are selectively powered to form content on both sides of thermal media passing thereby. Different sides of the thermal media have thermal dye layers with different activation sensitivities. The printing device also includes a media transport system to move the thermal media by the single thermal printhead. A controller of the printing device generates printed content on both sides of the thermal media in a single pass by powering the single thermal printhead based on both content to be formed on a first side and content to be formed on a second side.