AMF is an XML-based additive manufacturing file format designed for advanced 3D Printing workflows. AMF supports mesh geometry, materials, colors, textures, lattice structures, and manufacturing metadata within a single file.
The format was developed as a successor to limitations found in STL and was standardized by ASTM International under ASTM F2915. AMF files commonly use the .amf file extension.
AMF was created to provide richer manufacturing information for additive manufacturing systems while maintaining compatibility with polygon-based geometry workflows.
What Is AMF?
AMF stands for Additive Manufacturing File Format.
The format was designed specifically for additive manufacturing technologies and supports significantly more information than traditional STL workflows.
AMF files may contain:
- mesh geometry
- curved triangle definitions
- material assignments
- color information
- textures
- lattice structures
- object hierarchies
- metadata
- multiple objects
Because of its XML-based structure, AMF is both machine-readable and extensible.
AMF Geometry Representation
AMF primarily represents geometry using polygon meshes.
Common geometry elements include:
- vertices
- triangular faces
- curved triangles
- object groupings
- coordinate systems
Unlike basic mesh formats, AMF can also describe curved surfaces more efficiently through curved triangle definitions.
This can reduce visible faceting while maintaining smaller file sizes compared to highly tessellated meshes.
AMF in 3D Printing
AMF was designed specifically for additive manufacturing workflows.
A typical workflow may include:
- Creating geometry in CAD software
- Exporting the model as AMF
- Importing the file into a Slicer
- Defining manufacturing settings
- Generating G-code
- Printing the object using a 3D Printer
AMF allows manufacturing data and geometry to remain bundled within a unified file structure.
AMF vs STL
AMF and STL are both additive manufacturing formats, but they differ significantly in capability.
| Format | Material support | Color support | Metadata support |
|---|---|---|---|
| STL | No | No | No |
| AMF | Yes | Yes | Yes |
Compared to STL, AMF supports:
- multiple materials
- object colors
- textures
- lattice structures
- manufacturing metadata
- curved triangle definitions
STL remains more universally supported because of its simplicity and long industry history.
AMF vs 3MF
3MF and AMF were both developed to improve additive manufacturing workflows beyond STL limitations.
| Format | Structure type | Typical ecosystem |
|---|---|---|
| AMF | XML-based | Open additive workflows |
| 3MF | ZIP/XML package | Modern commercial printing |
Compared to AMF, 3MF often provides:
- stronger software ecosystem support
- better workflow integration
- improved packaging systems
- broader modern adoption
AMF remains important as an open standardized additive manufacturing format.
Curved Triangles in AMF
One unique feature of AMF is support for curved triangles.
Traditional mesh formats approximate curved surfaces using many flat triangles.
Curved triangles allow AMF to:
- reduce visible faceting
- preserve smoother surfaces
- lower file size requirements
- improve geometric approximation
This feature can improve surface quality in additive manufacturing workflows.
Materials and Multi-Material Printing
AMF supports advanced material definitions for additive manufacturing systems.
Material information may include:
- color assignments
- density values
- material mixtures
- texture information
- graded material transitions
This makes AMF suitable for:
- multi-material printing
- color printing
- experimental additive manufacturing
- industrial fabrication systems
Advantages of AMF
AMF offers several advantages over older additive manufacturing formats.
- support for materials and colors
- metadata preservation
- curved surface representation
- support for lattice structures
- extensible XML structure
- improved manufacturing information
These characteristics make AMF more capable than simple mesh-only formats.
Limitations of AMF
AMF also has several limitations.
- less universal support than STL
- limited adoption compared to 3MF
- larger software ecosystem fragmentation
- inconsistent implementation across slicers
- reduced compatibility with older systems
Because of these limitations, many modern workflows prefer 3MF despite AMF's technical capabilities.
Common Software Supporting AMF
| Software | AMF support type | Typical use |
|---|---|---|
| Cura | Import support | 3D printing |
| PrusaSlicer | Partial support | Additive manufacturing |
| MeshLab | Mesh processing | Geometry workflows |
| FreeCAD | Export support | Open-source CAD |
| Netfabb | Import and repair | Additive manufacturing |