A print bed is the surface of a 3D printer where a print head lays down the materials that make up a 3D print. A 3D printer requires the print bed to be level and flat in order to successfully produce layers of media in filament form that make up a 3D-printed object.
Standard original equipment print beds may be made of plastic, aluminum or glass. For better results, a print bed is sometimes lined with an adhesive, which can be a commercial product or a homemade treatment like a glue stick or blue painter’s tape.
The two main properties of the print bed surface that significantly affect 3D print quality are adhesion and, almost inversely, releasing the print when cooled. The variety and effectiveness for use from one media to another can require research and experimentation to perfect.
Adhesion determines how stable the first layer is, and thus has a huge effect on the accuracy of the entire print. If the bottom layer moves, it will affect the placement of other layers. When part of the print comes unstuck from the bed, especially with larger temperature differentials, the result of uneven cooling is called warping. Heat beds help prevent this issue by managing the cooling rate through a maintained temperature to help keep adhesion consistent.
Print release when cooled is also important to ensure the print can be removed from the print bed. Even if only one part sticks, it can break and ruin the print or damage the bed. The goal is to find an adhesive that helps the print stick and stay in place on the bed but is not strong enough to make detaching the print impossible.