November 23, 2020
pla vs petg 3d printing guide cover

PLA vs PETG: Which is the Best Filament for 3D Printing?

PLA and ABS are the two most commonly used 3D printer filaments, but PETG is emerging as a popular middle ground between the two. The PLA vs PETG war heats up when you learn of PETG’s great layer adhesion, strength and impact resistance — could it become the next go-to filament?

Let’s find out, by comparing PLA and PETG filaments. We compare them across 3D printing factors, like how error-prone and easy they are to 3D print, which filament creates better looking parts, as well as how environmentally friendly, which is cheaper, and more.

PLA vs PETG: 3D printing factors

Print temperatures, heated bed & build surface

Overall, PLA is easier to 3D print than PETG, and is more forgiving of any errors made in your 3D slicer settings or less-than-perfect temperatures. PLA prints at lower temperatures than PETG – 180-220C compared to 220-260C – and doesn’t require a heated bed to print, whereas PETG should be printed with a heated bed.

When printing PETG, you also need to be careful that you use enough adhesor to prevent PETG from sticking too well to your build surface. This is especially true if you use PEI sheets, as PETG is so sticky that it can rip parts of the PEI sheet or even your print bed off as you remove your part. This is because PETG has the best layer adhesion of any filament, leading to strong and durable models, but also creates these problems. PLA 3D printed parts are much easier to remove after printing.

PETG oozes and stirngs more than PLA, though PLA is also known for its stringing, so it is important to optimize your print settings in your 3D slicer to counteract this.

pla vs petg 3d printing factors

PLA vs PETG: which is best for supports / warping

A key advantage for PLA is how easy supports are to remove compared to PETG.

While PLA supports can be removed without much issue, PETG’s stickiness means supports are difficult to remove, often leaving visible marks that affect surface finish. If using a dual extruder 3D printer, you have more options for complementary support materials if printing with PLA, than with PETG. This makes PLA a more suitable filament for 3D printing parts with intricate geometries or complicated designs that require supports.

Both PLA and PETG have minor shrinkage after printing as the part cools, which should not cause much issue. Neither are known for warping badly, unlike other filaments such as ABS. PETG is recommended however to print slower than with PLA, as it is less forgiving with errors and inconsistencies.

PLA vs PETG: Post-Processing

PLA is considered better for post-processing, as firstly it can be painted with acrylic paint for any custom colors. PETG is difficult to paint as it is naturally more slippery.

It is also easier to glue PLA parts together. You’ll need a super-strength glue to stick PETG parts together, but again it can be done.

PLA vs PETG: Which is more expensive?

PLA is slightly cheaper than PETG, starting at around $20 per kilo. PETG starts at around $25 per kilo, with more industrial versions costing around $55.

We recommend the following PLA and PETG filaments:

Part quality factors

Though PLA and PETG are known to have similar densities, PLA is notably more brittle and snaps far easier if put under significant pressure. PETG is more durable, stronger, and features better impact resistance, due to its increased flexibility.

One of the main drawbacks of PLA 3D printer parts is that they begin to deform at low temperatures, starting at around 55-60C. This, combined with its lack of protection against sunlight, rain and conditions outdoors, render PLA ineffective as a material for outdoor or high temperature use parts. PETG on the other hand can handle higher temperatures (up to around 80C), as well as low temperatures, rain and sunlight.

pla vs petg part quality and aesthetic factors

Functional parts vs aesthetics

For functional parts used for rapid prototyping, PETG is the superior choice. It offers better strength, and its increased flexibility is better for functional parts that need some springiness.

However, for a part that is only needed for aesthetics, and will not be used in high temperatures or for functional use, PLA is the more attractive option. It is also worth noting that PLA scratches less easily than PETG, which is notorious for being easily marked.

To conclude, PETG offers far better part quality, but PLA can create better looking parts.

Colors, Different Blends & Aesthetics

PLA vs PETG: Color Options

There are more color options for 3D printing PLA than PETG, though with PETG you should still be able to find any color you need within reason. 3D printing companies such as ColorFabb offer complete customization in ordering any shade of PLA you want, which is not available with PETG.

PLA vs PETG other factors

PLA vs PETG: Different Blends

PLA has many more options for different blends, for those looking to create custom 3D prints mixed with carbon fiber, bronze, stainless steel, or even niche picks like conductive PLA. PETG has far fewer options, owing to PLA’s higher popularity.

Some interesting PLA blends we recommend include:

PLA vs PETG: Which looks best?

For a glossy and somewhat transparent finish, PETG is ideal. There are also transparent forms of PLA, but PETG’s natural glossiness and shininess with this transparent finish makes it the better option for these types of 3D prints.

Arguably, PLA is capable of creating parts with finer details, and is boosted by having no issues with supports that could potentially leave marks on the object. Some will instead prefer PETG’s shiny finish however, so preference is down to the user.

Other factors

PLA vs PETG: Which is more environmentally friendly

Undoubtedly, PLA is the better material for the environment. Not only can it be recycled, but PLA is also biodegradable, and will never sit around in landfill for hundreds of years.

This is because PLA, unlike most other filaments, is not formed of petroleum-based compounds, but is created from materials like cornstarch, a renewable resource. In theory, with enough crops you could grow enough PLA filament to supply the world’s plastic demand without requiring any non-renewables, which could then be degraded naturally after use.

On the other hand, PETG is not biodegradable, though it is recyclable.

PLA vs PETG: Which is more hygroscopic

Both PLA and PETG are hygroscopic, perhaps PETG slightly more so. This means that the materials absorb small amounts of moisture from the air, which worsens the material’s quality by making it more brittle and giving it a rougher texture.

To avoid this, we recommend storing PLA or PETG in a filament container where it is sealed away from outside air that would affect it. If your PLA or PETG filament has been exposed to air for a long time, consider purchasing a filament dryer to dry filament and remove accumulated moisture.

We recommend the following:

Food safety

Both PLA and PETG are considered food safe, though you will need to check your particular filament brand and type to confirm this. It is important to note however that when printing with these two food-safe filaments, small gaps in between layers can still host bacteria that can affect food and drink.

Conclusion

To conclude, PETG is the better filament for functional parts as it is stronger, remains solid at higher temperatures, and can take harder impacts. On the other hand, PLA is easier to print, comes in more colors and blends, and is better for printing supports.

Neither is superior to the other, and both have areas where they excel. In choosing whether to 3D print with PLA or PETG, consider how strong the part needs to be, whether the part is more aesthetic or functional uses, and how good quality you need the part to be. Then compare these needs to this PLA vs PETG guide and you should know which filament is best for your 3D printing needs.