FDM vs FFF: What Do These 3D Printing Terms Really Mean?

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Where Did FDM Come From?

Back in the late 80s, this guy Scott Crump came up with a clever way of building objects by melting plastic and squirting it out layer by layer.

Pretty much the process we all know today.

He patented it, and his company Stratasys gave it a shiny name: Fused Deposition Modelling, or FDM. Sounds fancy, right?

For a while, FDM was the term. If you were in the industry, if you were buying expensive machines, or if you were reading academic papers, FDM was everywhere.

How the Maker Community Created FFF

Now fast forward a bit.

In the mid 2000s, along comes the RepRap project. This was Adrian Bowyer’s big idea: build a 3D printer that could mostly build itself, make it cheap, and share it with the world. A proper open-source dream.

But there was one catch.

They couldn’t just go around calling it FDM because Stratasys owned the trademark. So they coined their own name: Fused Filament Fabrication, or FFF. Same process, same melted plastic, just a different label. And in a way, it became a kind of badge of independence.

I kind of like that little rebellion.

So that’s the backstory. FDM was the original, locked up in patents and trademarks, while FFF was the open-source alternative that the DIY crowd embraced.

FDM and FFF: Same 3D Printing Process Explained

Here’s where it gets interesting though.

On a technical level, there is no difference. FDM and FFF both involve feeding a filament of plastic into a hot nozzle, melting it, and laying it down in layers until you’ve got your object. The printer’s got a few main parts: the system that feeds the filament, the hot end that melts it, the motion system that moves everything around, and the bed where your part slowly comes to life.

Doesn’t matter if you call it FDM or FFF, the setup is basically the same.

The only real differences show up in how the machines are marketed and used.

Stratasys’s FDM printers are these big industrial beasts. They’ve got enclosed heated chambers, certified materials, fancy proprietary software, and they’re built for industries like aerospace and medical where reliability is everything. You pay a lot, but you get consistency and certification that makes them suitable for regulated fields.

FFF, on the other hand, became the people’s term. The printers that came out of the RepRap movement were cheap, open-source, hackable, and often sitting on someone’s desk at home. Think of machines like the Prusa or Creality Ender. They might not have the polished industrial feel, but they’re accessible, fun to tinker with, and constantly evolving thanks to the community. Things like auto bed levelling, better slicers, and even multi-material upgrades often started in the FFF crowd before trickling up.

Why the Gap Between FDM vs FFF Is Shrinking

The Role of Standards: Material Extrusion (MEX)

Another layer to this is how the standards bodies are trying to settle the debate.

ISO and ASTM, which love making everything official, came up with a neutral term: Material Extrusion, or MEX. That way they don’t have to pick sides between FDM and FFF.

In theory it makes sense. But in practice, people keep using FDM or FFF depending on whether they’re in industry or the open-source world.

Old habits die hard.

And here’s something I find kind of nice. This split actually ended up helping innovation.

Stratasys and FDM machines went down the path of certification, reliability, and high-end materials like ULTEM or carbon fibre composites.

Meanwhile the FFF community pushed the boundaries on affordability, accessibility, and rapid improvements.

Together, they’ve kind of fed off each other.

Take aerospace as an example. Stratasys FDM systems are used to make real flight-ready parts because they can certify the materials and processes. At the same time, the hobbyist world is pushing cheap new printers that allow engineers at home to experiment, prototype, and learn without needing a six-figure budget.

One drives stability, the other drives creativity.

Looking Ahead

Looking ahead, I think the whole FDM vs FFF thing will matter less and less.

As open-source machines keep getting better, more businesses will use them in serious ways. And as the standards bodies push “MEX” as the official language, the terms might blur into history. But I have a feeling people will keep saying FDM or FFF because they carry more story than “MEX” ever will.

So next time someone argues about whether a printer is FDM vs FFF, you can just smile and say, “It’s both.” The plastic doesn’t care what you call it.

What do you think? Does the name matter to you, or do you just care if the print sticks to the bed?

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