Aaron Pearson
Vice President of Public Relations

By Todd Grimm, Additive Manufacturing Users Group, AM Industry Advisor

In my last post, I made light reference to the need for science and technology to catch up to 3D printing’s abilities for it to really take off. The point was that lacking simulation and analysis of functionally graded materials, the practicality of using advanced material capabilities are somewhat limited.

However, apart from materials, I believe there is an even more pervasive technology gap - one that exists between the CAD and the 3D printer and hinders functionally graded materials as well as full-color printing and microstructures: The simple STL file format is unable to communicate such sophisticated design elements!

Chess Piece in AMF Format

There is, however, good news on the horizon — the AMF (additive manufacturing file) format is an XML-based, open-source framework for data exchange. As Hod Lipson, associate professor at Cornell University and chairman of ASTM’s Design Task Group, posted on, ASTM has adopted AMF as a standard, lightweight (small file size) yet robust bridge between CAD and 3D printers. This file format contains all the information needed to make the most basic or the most complex parts you can conceive.

The AMF format defines:
1. Multi-materials, including functionally graded Digital Materials.
2. Multi-color, including gradients.
3. Complex structures.

If you’re not ready for those advanced capabilities, AMF still has plenty to offer:
1. Units of measure (no more guessing if the file is in inches or millimeters).
2. Curved patches (facets that mirror surface contours).
3. Part constellations (one definition for multiple copies).
4. Small files (compressed AMF is 50% smaller than compressed, binary STL).

The AMF team has even developed an STL to AMF translator!

But don’t break open the champagne quite yet. As Hod pointed out, this is a bit of a chicken-and-egg story. To make AMF work, software has to export the file and 3D printers have to read it. But without files to import, hardware manufacturers may have little motivation to support AMF. On the other hand, without 3D printers that can read AMF, software developers don’t have any demand for this new format.

That’s where you come in! If you want the power of the AMF file, let your vendors know. Contact your 3D printer manufacturers and CAD suppliers and tell them that you want AMF, now!

For more information on the AMF file format, visit its Wiki.