November 29, 2020
pla filament for 3d printing guide

PLA Filament: The Complete Guide (& Best PLA 3D Printers)

Pleasant-smelling, natural, and a favorite of both beginners to 3D printing and eco-warriors, PLA filament is the world’s most popular 3D printing material. But why should you print with PLA rather than ABS, or PETG? We explain the advantages of PLA, disadvantages, printing best practices for the best results, and more in our complete PLA 3D printing guide.

  • This article focuses exclusively on PLA. For a short guide to all filaments, we have a complete 3D printer filament guide
  • We also have a full guide to ABS filament.
  • For a comparison between PLA and PETG, check out our guide comparing PLA vs PETG.

A Short History of PLA in 3D printing

Polylactic Acid, shortened to PLA, was first used for 3D printing by Vik Olliver, one of the first champions of the RepRap movement. Struggling to find a good material for their first RepRap 3D printers to use, Vik Olliver collaborated with a New Zealand-based plastic manufacturer to get the first PLA filament made. It proved effective, and now 15 years later PLA is the most widely used filament in the world.

vik olliver pla reprap
Vik Olliver (right), who came up with the idea to use PLA in 3D printing, next to his first RepRap printer.

What is PLA?

PLA is one of the simplest filaments to print with, which is why we recommend it to 3D printer beginners and those looking for a 3D printer for kids. It prints at a low temperature, does not require a heated print bed (though it still helps!), and there are almost infinite combinations of colors or blends of PLA with different mechanical properties for any application you could possibly think of.

PLA 3D printing characteristics

PLA melting point

Typically, PLA melts between 130 and 180C, though this depends on the blend and other factors.

PLA 3D printing temperature

Any temperature between 180C and 220C can work, with around 210C seen as a consistent temperature to avoid stringing and allow for good layer adhesion. Again, this depends on the type and brand of PLA you use – always check this before printing.

Should you use a heated bed when 3D printing PLA?

Using a heated print bed is optional with PLA as it does not warp hugely, but we still recommend using one for the best results. Depending on the type of PLA filament you use, we recommend a heated bed at between 30-70C.

PLA filament sizes

PLA comes in both 1.75mm and 2.85mm options. Most affordable 3D printers use 1.75mm nowadays, but some, such as the Ultimaker 3, one of the best 3D printers of the last few years, and BCN3D Sigma, use 2.85mm, sometimes referred to a 3mm filament.

Size difference between 1.75mm and 2.85mm PLA.

All key PLA statistics are listed below:

  • PLA density: around 1.24 g/cm³ (changes if blended with other materials or filaments)
  • PLA glass transition temperature: 60-65C
  • PLA melting point: 130-180C
  • PLA 3D printing temperature: 180-230C

Advantages and Disadvantages of PLA

pla filament advantages and disadvantages

Benefits of PLA Filament

  • Easy to print with: whereas filaments like ABS warp to such an extent that long, flat parts need special treatment, PLA prints at a lower temperature and warps considerably less. As a result, PLA does not even require a heated bed, making the 3D printer safer for kids, though a heated bed still helps create better quality parts.
  • Biodegradable and environmentally friendly: PLA comes from a renewable resource, usually from corn, and under industrial composting conditions will degrade. With enough corn crops in your back garden, and the means to turn it into PLA, you could have a renewable 3D printing house for a domicile!
  • No harmful fumes when printing: whereas filaments like ABS can create smelly fumes that may be harmful, PLA is safe and odorless, as it is formed from crops rather than petroleum-based compounds.
  • Cheap: PLA is one of the cheapest filaments around, and for the price, offers good surface finish and strength of parts.

Drawbacks with using PLA filament

disadvantages of pla for 3d printing brittle, strings and oozes, and low temperature resistance
  • Brittle: not suitable for prints which need to be malleable or twisted in any way. Some PLA+ filaments somewhat improve the brittleness issue, but for these parts TPU or other more versatile filaments are better suited.
  • Problems with oozing: need to set up effective cooling fan system and retraction settings to counteract this.
  • Not ideal for durable parts: has a glass transition temperature of between 60-65C, so PLA is not suitable for parts to be used outside, or in hot temperatures. Moreover, filaments like PETG and ABS have stronger mechanical properties, so are better for functional parts.
  • Not food safe: despite PLA being used with food packaging, PLA filament is not food safe. There are however food safe variants for applications where this is important.

Best PLA Filament

Some PLA filaments we recommend include:

Best PLA 3D Printers

There are a number of great PLA 3D printers out there. Some, such as the Dremel 3D20, focus purely on PLA 3D printing, whereas some can also print tougher filaments.

PLA 3D printers buyer's guide (all price ranges)

PLA 3D printerHeated bed?Build volume (mm)PriceAvailable at
Creality Ender 3Yes220 x 220 x 250$250Amazon here
Dremel 3D20No230 x 150 x 140$650Amazon here
Qidi Tech X-ProYes230 x 150 x 150$699Amazon here
Flashforge Creator ProYes227 x 148 x 150$799Amazon here
Ultimaker S3Yes230 x 190 x 200$3,499Dynamism Store here

How to get the best results from PLA 3D printing

pla filament best practices tips and tricks for 3d printing
  • Reduce oozing: because of PLA’s fast flowing speed, oozing and stringing can occur, making prints look less polished. By optimizing your retraction settings you can mostly prevent this from happening, Simplify3D have a guide here for working on this in your 3D slicer.
  • Use a cooling fan: a cooling fan makes a huge difference in quality, and prevents the plastic from stringing and creating imperfections. Having your fan set to high helps layers to cool before the next layer prints, especially on miniatures.
  • Print slower on smaller models: Small parts take less time to print each layer, leaving them less time to cool. Running your printer slower for small parts ensures layers have enough time to cool, reducing any deforming.
  • Optimize extruder temperature: different PLA blends can have very varied optimum temperatures. For example, carbon fiber-filled or wood-filled filaments are going to have very different melting points. Check the best temperature for your particular filament before printing, and if stringing is occurring then reduce the temperature slightly.
  • Use the right build surface: Matterhackers recommend blue builder’s tape for PLA, which you simply need to cover the bed with strips of tape. Other surfaces like PEI film or just printing directly onto a glass heated bed also work.

Types of PLA Filament

There are actually even more than the ones listed here. These are some commonly seen variants:

  • PLA+: an improved version of PLA blended with other plastics. It is known for being less brittle – a major drawback of PLA – and absorbs less moisture, as well as offering better mechanical properties.
  • Wood-filled: printed parts look wooden
  • Metal-filled: gives parts a realistic metallic look. Mixes include stainless steel blends, aluminium, copper, brass and bronze PLA filaments.
  • Carbon fiber infused: for very strong, lightweight parts
  • Flexible PLA: mixed with TPU or similar
  • Aesthetically modified PLA: including glow-in-the-dark PLA, transparent or translucent blends, silk-like PLA, glittery and sparkly PLA, fluorescent, and color-changing PLA based on factors such as heat or UV light.
  • Conductive PLA
  • Lightweight (LW-PLA): designed so it foams when melts, spreading to a larger surface area to print lighter parts that require less filament to print. It’s more expensive, but allows for up to 65% lighter parts that print quicker.
wood filled pla 3d printed part
A bowl printed using wood-filled PLA. Credit: BrutalBoogz on Reddit.

PLA Applications

PLA is mainly used in rapid prototyping, to create low-cost, accurate parts with a good surface finish. Though not terrifically strong, PLA is great for aesthetic testing for shape or size.

PLA is often also used by makers and fans to create miniatures, of any particular style that they are die-hard fans of. Custom DnD characters, classic memorabilia models such as WW2 planes or retro 3D printed cars are commonly made from PLA. Cosplay props are another common application that work great with PLA, as well as general decorations.

Outside of 3D printing, PLA is often used in food packaging as well as in medical applications.

How to Store PLA

PLA is slightly hydroscopic – which means it absorbs very small amounts of water from the air. This can, over time, reduce print quality by making the filament more brittle, and bubbly. Other filaments such as PVA and Nylon are affected far worse however.

Ideally, to maintain optimum printing conditions with your PLA, you should store it in an airtight filament container. We have linked to some we recommend below.

polymaker polybox ii
The Polymaker Polybox II can hold two filament spools, and is linked above.

PLA Post-processing

For post-processing, despite the many colors of PLA available, you can also still acrylic paint to change the colors of prints, or paint certain areas such as for 3D printed miniature figures. You can also polish or sand parts in the post-processing of PLA 3D printed parts for better results.

Making PLA filament

PLA is made by adding enzymes to starch harvested from crops such as corn to convert it into dextrose. Any pigments are added based on what color filament you want, as well as any blends for any hybrid type of PLA.

The mixture is fermented into lactic, which is then turned into polylactide. The process to get it to become a plastic on a spool involves drying the mixture out, putting into an extruder and heated, to be extruded into solid filament.

The filament is then cooled and wound onto a circular spool so that it is then ready to print.

Is PLA biodegradable? And is PLA recyclable?

Many highlight the environmental benefit when arguing for the use of PLA in 3D printing and beyond, as it comes from a renewable resource rather than petroleum-based materials.

This is true, maize and other crops are renewable. However, we must also account for the opportunity cost of those crops being used to feed people – it is not such a cut-and-dried issue.

While undoubtedly avoiding non-renewables that pollute is a positive, it takes between 2 and 3kg of corn to create 1kg of PLA. To completely replace non-renewable plastic production would take food from hundreds of thousands of people’s mouths. With demand for these crops exploding as the population continues to increase, this becomes less and less feasible.

Additionally, while PLA is biodegradable, this is under conditions of high 55-70C temperatures. In normal day-to-day temperatures it could take 80 years to decompose.

As for recyclability, yes, PLA is recyclable if collected especially for PLA. If contaminated with other plastics like PET this affects recyclability, resulting in large amounts of PLA not being recycled simply because systems are not in place to specifically recycle PLA.

Conclusion

Overall, there is a reason why PLA is so commonly used: it’s a great filament for beginners, it prints well, doesn’t require any additional kit, and is cheap.

We do not anticipate any other filaments replacing PLA as the everyman’s 3D printer filament any time soon, and recommend it for anyone who does not want to upgrade their 3D printer parts, such as hot end or nozzle, to print tougher filaments like Nylon.