Choosing which materials to use for your next 3D printing project is getting a little more complicated. An expanding range of available supplies makes selecting the right filament for your product or project even more important. When considering PETG vs. PLA 3D filaments, ask, “What are the differences?”

Definitions

Filament names can seem like a crowded alphabet soup of acronyms. PETG stands for “polyethylene terephthalate glycol.” It is based onthe petroleum-derived polyethylene terephthalate (PET) but with glycol added to provide a lower melting point, high toughness and less warpage during cooling.

PLA stands for “polylactic acid.” It’s derived from plants, and it is industrially compostable. Its melting temperature is lower than PETG’s and it doesn’t require a heated print bed.

Properties

PETG is more flexible than PLA but produces a less attractive finish that can scratch easily. PETG is more resistant to water and chemicals than PLA, and PETG is more durable and more rigid than PLA. PETG is naturally transparent, making it a popular choice for plastic bottles.

PLA is easier to print with than PETG and easier to remove from the print bed. It’s available in a variety of colors. It’s less expensive than PETG, and while both types of 3D printing filament are recyclable, PLA is biodegradable under the right conditions, while PETG is not.

PETG is more prone to warping than PLA, and although it is said not to require an enclosure, one may be necessary to reduce warping.

While PLA doesn’t need a heated print bed or an enclosure, it tends to shrink just a tad more than PETG as it cools. PETG may be the better material for parts with strict tolerances.

Food Safety

Both PLA and PETG are considered food safe, although PETG is more often used for food contact due to its resistance to moisture and UV light. However, the addition of color additives may bring food safety into question. If you are printing an item intended for food contact, stick with non-coloured filament or make sure it’s certified food safe with the manufacturer.

Medical Uses

PLA can break down into lactic acid. This process takes a long time, even in industrial composting facilities. Still, PLA can break down faster within the human body, making it a better choice for medical implants intended to dissolve.

PETG can withstand medical sterilization, making it a better choice for permanent medical implants and packaging.

Choosing PLA 3D printing material over PETG may be a matter of the level of concern for sustainability, ease of printing, and durability. The differences between PETG and PLA are subtle but significant. Where flexibility and durability are the primary need, PETG may be the better choice. Where sustainability and ease of printing are needed, go with PLA. If you want the best of both worlds, check-out our BioDuro PLA!