STL file format – Glossary

STL (Stereolithography) – file format for 3D printing

The STL format is one of the most important file formats in the field of 3D printing and computer-aided manufacturing (CAM). It was originally developed by 3D Systems for stereolithography and has established itself as the standard for exchanging 3D models.

Features of the STL format

  • Surface model: STL only saves the geometry of a 3D object, but not colors, textures or material properties.
  • Triangle mesh: The model is approximated by a large number of triangles (facets) that define the surface of the 3D geometry.
  • ASCII & Binary: There are two variants – the ASCII STL (readable, but larger) and the binary STL (more compact and efficient).
  • No scaling units: STL files do not contain metric information, so the unit (e.g. mm or inches) must be defined depending on the application.

Application of STL

  • 3D printing: STL is the standard format for 3D printers, which use it as the basis for calculating the print paths.
  • CNC production: STL is also used in milling and laser technology to prepare models for machining processes.
  • Simulations & visualizations: Engineers and designers use STL to visualize prototypes and check for errors.

Advantages and disadvantages

Advantages:

  • Widely used & compatible with almost all 3D printers
  • Simple structure without complex metadata
  • Supported by almost all CAD programs

Disadvantages:

  • No information on colors, materials or textures
  • High memory requirement for complex models with many triangles
  • No direct support for volume or structural information

STL is still one of the most important file formats for 3D printing and rapid prototyping. However, modern alternatives such as OBJ, AMF or 3MF offer more functions and are more advantageous in certain applications.

Dieser Beitrag ist auch verfügbar auf: Deutsch (German)