AMF file: what it is and what to use instead

What AMF can do and why it never caught on

AMF is the ISO/ASTM 52915 standard and was created as a worthier successor to STL. It is an XML file that can store several materials, colours, lattice structures and curved triangles, so curves are not built from flat facets.

In practice only a handful of programs support it today. Among hobby printers and slicers, 3MF has all but replaced it, because it solves the same problems and almost everything can read it. You may still come across older AMF files on research websites or in large industrial systems.

How AMF differs from STL and 3MF

• STL has only a surface of flat triangles, with no colours or units.
• AMF knows units, colours, several materials and curved surfaces, but few programs support it.
• 3MF can do about as much, is widespread and opens in every common slicer.

So if you have a choice, pick 3MF when exporting. AMF only makes sense when your CAD program or scanner offers nothing else.

What to do with AMF when ordering

We do not take AMF files in the calculator. We accept STL, 3MF, OBJ and STEP up to 50 MB. If you only have the model as AMF, open it in a program that can read it (for example PrusaSlicer, Fusion or FreeCAD) and export it as 3MF or STL.

Watch the units: AMF stores them explicitly, STL does not. Check the dimensions after exporting. If they come out 25.4 times larger or smaller, you can fix that with the scale in the calculator. For multicolour printing, send a 3MF with colours assigned, because colour changes add a purge tower and time, and so cost.

When you will meet AMF and what to do with it

An AMF usually arrives from an older 3D scanner, an academic project or a company system that exports it as one of its options. The file is often compressed (the .amf extension is really a zip containing XML), so if nothing else can open it, try unzipping it. Inside you will find volumes, materials and possibly colours.

When you need to print a model quickly, do not go looking for a special program. Open it in PrusaSlicer or FreeCAD and save it in another format. You will then see the price and delivery date straight after uploading in the calculator.