What is the purpose of a heated bed in 3D printing?

A heated bed in 3D printing serves to improve adhesion of the print to the build surface. When the printing process begins, materials like PLA, ABS, or PETG can easily warp or lift due to cooling. A heated bed maintains a consistent temperature during the printing process, ensuring that the base layer of the printed object does not cool too quickly. This helps to bond the material more effectively to the build surface, minimizing issues such as warping and improving the overall stability and quality of the print. The ability of the heated bed to keep the first layers warm helps in achieving a successful print, especially with materials that are prone to thermal shrinkage.

The other options pertain to factors that do not align with the fundamental role of a heated bed in the 3D printing process. Cooling down the print would create the opposite effect of what is needed for adhesion, enhancing color quality is not a primary function of a heated bed, and reducing the size of a printed object goes against the nature of additive manufacturing, which builds up layers rather than reducing size.