PLA, or polylactic acid, is the most common material of choice for filament deposition modelling (FDM) 3D printers. It looks like plastic, smells like plastic, and probably tastes like plastic. It’s the filament that most of us start with, and it’s the one that many of us should stick with in all but the most exceptional circumstances.

Basic PLA is cheap and plentiful

Print with all the colors of the rainbow

Credit: Patrick Campanale / How-To Geek

Basic PLA is by far the cheapest and most readily available 3D printing filament. I can walk 10 minutes around the corner from my house and buy a few rolls of it from a brick-and-mortar office supply store, and if that’s not a sign that 3D printing has hit the mainstream, then I don’t know what is.

Since basic PLA is the “default” filament for these printers, there are a vast number of brands to choose from at a variety of price points. While printer manufacturers like Bambu Lab and Prusa have their own lines of filament, there are “cheaper” brands like SUNLU and eSun that serve as compelling alternatives to name-brands for less money.

Sticking with basic PLA will give you the widest range of colors to choose from, including different shades of the same colors. You can even buy recycled PLA filament from companies like Printerior Designs (who will also accept your old PLA scraps in exchange for credit).

PLA is a low-toxicity filament

You should still crack a window

Credit: Tim Brookes / How-To Geek

It’s generally not considered safe to share a confined living space with a 3D printer. This is especially true when printing materials like Nylon or ABS, the latter of which releases styrene, which can lead to irritation of mucous membranes, nausea, headaches, vomiting, and even cause you to lose consciousness.

While you should always print in a well-ventilated space, PLA is not associated with such dangerous side effects. Just keep in mind that we don’t know what the long-term effects of being exposed to the volatile organic compounds (VOCs) and ultrafine particles (UFPs) produced when printing PLA will be.

You’re less likely to encounter print problems with PLA

It’s the easiest material to work with

Credit: Tim Brookes / How-To Geek

Failed prints can be frustrating and wasteful. Not only is PLA cheap to begin with, but it’s also considered to be the easiest filament to print with. It’s less likely to warp, requires relatively low temperatures, and has no fancy nozzle requirements (in its most basic form).

PETG is also considered relatively easy to print with, and it provides better strength than PLA, but it’s also more susceptible to stringing and moisture issues. ABS is notorious for warping, while TPU can present quite a challenge on account of its flexible nature.

Even fancy PLA filaments can be abrasive (and some require harder nozzles)

Not all PLA filaments are created equal

Credit: Hatchbox

PLA has been combined with all manner of materials to create some interesting new filament blends. There’s PLA wood, which contains actual wood, can be sanded, and even finished like wood. There’s also PLA metal, which contains iron and will rust for that ferrous look. There’s even glow-in-the-dark PLA, which includes ingredients like strontium aluminate to achieve the desired effect.

While these are undeniably cool, they’re also more abrasive than basic PLA. Most will require a hardened steel nozzle, since they will shred a standard brass nozzle on account of having a higher hardness rating. I’m not saying stay away entirely, but you might want to only break them out occasionally.

PLA is strong enough for the vast majority of prints

Not everyone needs PPA-CF

Credit: Tim Brookes / How-To Geek

This might seem controversial, but before you rush to the comments to point out that you absolutely need to print certain items with stronger filaments, consider what the average user is printing at home. For items that mostly stay in your house and that don’t need to withstand a huge amount of force or weight, PLA is a great choice.

You can do all sorts of things with PLA, like print your own speakers, create housings for ESP32 smart home projects, and make already-excellent IKEA products even better. You can even improve a print’s strength of learning how to orient it properly on the print bed.

Low heat resistance can be a good thing

Understanding glass transition temperature

Credit: Zion Brock / ZionBrock.com

PLA is known for its relatively low heat tolerance. While it prints at around 190-230ºC, the glass transition temperature of PLA is somewhere around 65ºC. That means PLA will start to warp and bend permanently when it reaches that temperature.

This means you can do some pretty cool things with PLA that are harder to do with other, more heat-resistant filaments. By far my favorite of these is thermoforming, where you heat a PLA print to the glass-transition temperature and mold it into the shape you want. This is used to great effect in a 3D printed old-timey radio project by Zion Brock to achieve an effect that looks like speaker cloth has been stretched into place.

You can also do other things like PLA welding, where you heat up PLA with friction or use a soldering iron to melt plastic in between two parts you want to join. You can also achieve a similar effect with a 3D printing pen, which is an excellent use for your filament leftovers.

It’s marginally more environmentally-friendly than many other filaments

I said marginally

Credit: Sydney Louw Butler/How-To Geek

3D printing isn’t necessarily the most eco-friendly hobby in the world. The prevalence of 3D printed slop is a source of frustration for me, and I definitely think twice about printing something and contributing to the problem. The one small consolation to take from this is that PLA is technically a biodegradable plastic.

This comes with a big caveat. PLA is only biodegradable under industrial conditions, which requires temperatures of 60ºC or higher and a blend of specific microbes. It won’t just break down in your compost; you’ll need to go out of your way to recycle it properly.

The adoption of PLA has increased to the point where it’s used in medical devices, food containers, packaging, agriculture, and more. Hopefully, PLA recycling will become more viable in time.

Bored of PLA? That’s too bad. Thankfully, there are some more exotic filaments out there to sink your teeth into.