What the standard defines
A package — a compressed archive with a defined structure — containing the model geometry as a mesh with explicit units, the build arrangement of one or more objects, and optional colours and materials. Extensions published by the consortium cover further data, and slicers add their own project settings inside the package.
What it does not promise
No cross-slicer settings guarantee: vendor data in the package may be ignored by other programs. No printability: a 3MF can still contain geometry a printer cannot make. No design history from CAD. No universal support: older tools and some model sites still work only with STL.
What it works with
Multicolour printers and their slicers, which rely on colour and object data. STL, for sharing plain shapes. G-code, which the slicer produces from the 3MF for one printer and one material.
Questions makers ask before buying
Will a 3MF saved in one slicer open with its settings in another?
The geometry and core data will; slicer-specific settings are often stored in ways only the same slicer family reads fully.
Is 3MF larger than STL?
It is a compressed package, so for the same geometry it is often smaller than a binary STL, even while carrying more information.
Last reviewed 15 September 2026