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If you’re new to the world of 3D printing, you’ve probably seen a lot of jargon thrown around. This can be particularly off-putting for a newcomer, despite how mainstream the hobby has become in recent years.

Everyone has to start somewhere, so let’s take a minute to demystify some of the more perplexing terminology you’d bound to encounter.

FDM

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FDM stands for Fused Deposition Modeling, and it refers to the most popular and common form of 3D printing where material is dispensed from a nozzle in layers to print a model. FDM is also known as material extrusion and Fused Filament Fabrication (FFF).

You might see people refer to FDM printers as filament printers, on account of the thermoplastic filament that is fed into the machines. FDM is by far the most popular print method among hobbyists on account of it being affordable, relatively non-toxic, and easy to clean up when things go wrong.

Filament

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Filament is essentially the “ink” used by FDM printers. It is commonly shipped on long spools and fed into the machine in a long spaghetti-like strand. Filament is heated to the point of being molten, and then reshaped by the print nozzle layer by layer to create models.

There are many different types of filament available, from the relatively cheap and accessible PLA to stronger ABS, PETG, TPU, and others.

SLA

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SLA stands for stereolithography and refers to the most common and accessible resin 3D printing process. Unlike an FDM printer, an SLA printer cures liquid resin using a UV laser that is projected onto a mirror, layer by layer. As the resin turns into a polymer, the build platform rises and the model “grows” out of the liquid resin.

DLP

DLP stands for digital light processing, and it’s another form of resin-based 3D printing. Unlike SLA, DLP uses light rather than lasers (which can also be LEDs), can be printed faster, but print quality isn’t quite as good.

Resin

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Resin, also known as photopolymer resin, is the liquid used in resin-based printers that use SLA, DLP, and other liquid print methods. Unlike filament-based printers, resin can be a lot messier to work with, and requires washing in solvent and curing under a UV lamp before the print can be used.

While some filament methods are relatively safe and non-toxic, resin typically requires protective equipment like respirators and gloves (plus a well-ventilated space) to use safely.

Slicer

A slicer is a type of software that converts a 3D model into instructions that can be interpreted by a 3D printer. It is named because it “slices” the model into different layers, so that the printer can reproduce these layers one by one. Some examples of slicers include PrusaSlicer, BambuStudio, and Ultimaker Cura, all of which are free and open-source.

Resin and material extrusion printers use different slicers because of the different methods in which the prints are produced.

Extruder

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Specific to the world of material extrusion-based printers, an extruder is the part of the printer that takes the filament and feeds it into the nozzle using a motor.

You may also encounter the term “Bowden extruder,” which refers to a specific type of extruder where the motor and other components are separated from the hot end, which can help speed up prints by cutting down on the weight of the extruder assembly.

Hot End

Also referred to as a “hotend,” the hot end is exactly what it sounds like: the hot part of the nozzle that’s responsible for heating filament in a material extrusion-based printer. The hot end can be heated to very high temperatures (think 200 to 300ºc), so you want to wait for it to cool before touching it or wear heat-proof gloves if you have no other choice.

You might also come across the term “cold end” to refer to the part of the extruder assembly responsible for feeding the filament into the hot end.

Benchy

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The cute little model of a boat designed as a way of testing a 3D printer’s quality and speed, complete with its own website. The first thing you’ll (probably) 3D print.

Infill

Infill refers to the internal area of a model that connects the edges of the model but is typically not seen. Measured in percentage points, the amount of infill used can have a big impact on the resulting model. Too little infill and the print will be weak, too much and the print will be heavy and potentially costly in terms of material used.

Striking a balance here is key. For small models and non-functional prints, infill of around 10% isn’t uncommon. For prints designed to be functional and withstand everyday use, 50% or greater is recommended. Some people choose to print proof of concept models with cheaper filament and low infill numbers to check fit and finish before committing to a final print.