FDM or FFF: What’s the Right Term for 3D Printing?

By on August 3rd, 2023 in Ideas, news

Tags: , , ,

In our 3D printed world, should we use “FFF” or “FDM”? [Source: Fabbaloo / LAI]

Another day, another misuse of the term “FDM”.

Here’s an example of something I read today:

“Fused Deposition Modeling (FDM) – also often referred to as Fused Filament Fabrication (FFF) – is a widely used 3D printing technology.”

Hold on, which is it? FFF or FDM?

I keep seeing people and companies using “FDM”.

And they are wrong.

FDM is the process invented by Stratasys in the 1980s, and one of the first two 3D printing processes discovered. Stratasys trademarked the term “FDM”.

Thus — legally — “FDM” refers ONLY to Stratasys equipment using that filament extrusion process. Any other company using “FDM” to refer to their equipment is wrong.

Yes, it may be the same physical process, since Stratasys’ original patents expired back in 2008 and since then many companies have deployed equipment using a version of Stratasys’ original process. But they cannot call it “FDM”.

Here’s an analogy that brings this concept home: should you say you’re going to “photocopy” that page, or are you going to “Xerox” that page? That is what I see when I read the many misuses of “FDM” in print and online.

The correct term for all (except Stratasys) is “FFF”, and that’s what we consistently use in this publication.

There’s one twist to this situation, however.

In the United States, trademarks are registered for ten year terms, and can be renewed. In other words, trademarks can indeed expire. At that point they can be freely used for whatever purpose.

Perhaps Stratasys has allowed the “FDM” trademark registration to expire?

I checked.

It has not expired.

Stratasys’ current in-force trademark registration for “FDM” [Source: USPTO]

In fact, it appears that the filing date for their latest renewal is 26 January 2021, meaning that FDM is theirs alone until at least 2031.

Or longer, should they choose to renew it.

The message here is that we should all be using FFF, not FDM, unless you happen to be a Stratasys employee or referring to their equipment.

When you see or hear someone using “FDM”, please take the time to correct them.


By Kerry Stevenson

Kerry Stevenson, aka "General Fabb" has written over 8,000 stories on 3D printing at Fabbaloo since he launched the venture in 2007, with an intention to promote and grow the incredible technology of 3D printing across the world. So far, it seems to be working!


  1. You got to use the standard ASTM ISO/ASTM52900-15 “Material Extrusion.” More descriptive too

  2. Well actually we should be using the correct ISO term, which is MEX( Material extrusion) because regardless of who is the manufacturer or machine brand. They all share the same principle including Stratasys.

    If as a media you inform the public both specialized and not so much, you SHOULD divulgate correct information and not the same wrong definitions over and over.

Leave a comment

Your email address will not be published. Required fields are marked *