STL
Also known as: STL File, Stereolithography
The most common 3D model file format for 3D printing, containing surface geometry.
STL (Stereolithography) is the most widely used file format for 3D printing. It describes the surface geometry of a 3D object using triangular facets.
How STL Works
- Model surface is broken into triangles
- Each triangle defined by 3 vertices and a normal vector
- More triangles = smoother curves = larger file
Pros and Cons
Advantages
- Universal compatibility
- Simple format
- Supported everywhere
Limitations
- No color information
- No material data
- No units (assumed mm)
- Can have errors (non-manifold, holes)
- Large file sizes for detailed models
STL vs. 3MF
| Feature | STL | 3MF |
|---|---|---|
| Color | No | Yes |
| Materials | No | Yes |
| Units | No | Yes |
| Compression | No | Yes |
| Metadata | No | Yes |
| Multiple objects | Limited | Yes |
Working with STL Files
Finding Models
- Thingiverse
- Printables
- MyMiniFactory
- Thangs
Creating Models
- Fusion 360
- Blender
- TinkerCAD
- OpenSCAD
Repairing Issues
- Meshmixer
- Netfabb
- PrusaSlicer’s built-in repair
- Windows 3D Builder
Best Practices
- Export at appropriate resolution
- Check for manifold errors
- Verify scale before slicing
- Consider 3MF for complex prints