Standard triangle language

Standard triangle language (STL), is one of many file formats used for 3D printing. For biomedical 3D printing from DICOM files, DICOM files must undergo image post-processing including segmentation and then be turned into an appropriate file format for printing. Currently (2019) STL is the most often used file format in biomedical 3D printing, although many other file formats, e.g. OBJ, 3MF or AMF, are less computationally expensive.

History and etymology

Many medical sources refer to STL as standard tesselation language , and the format is indeed a tesselation of triangles to represent the surfaces of objects for printing. Stereolithography, an extremely popular form of 3D printing for which STL was developed, includes the letters S,T and L, which led some technology writers to use the term STL as if it were a file format that implied stereolithography as the only process it is used in, however, this is now incorrect.