PETG (polyethylene terephthalate glycol) is a glycol-modified polyester 3D printing filament that balances the easy printing of PLA with strength, toughness, and moisture and chemical resistance approaching ABS.
Polyethylene terephthalate glycol is a modified form of PET, the polyester used in water bottles, with glycol added to the polymer chain to make it less brittle and easier to print than raw PET. As one of the 📝3D Printing Filament Types, it prints at nozzle temperatures of roughly 230–250°C on a bed of 70–85°C. PETG is hygroscopic, readily absorbing atmospheric moisture that degrades surface finish, so it is typically dried before printing and stored sealed.
Mechanically, PETG records a lower tensile strength than PLA — around 40–50 MPa versus 50–60 MPa — yet it is far tougher, absorbing impact energy and flexing instead of shattering. It resists water, many chemicals, and heat better than PLA, though it is more prone to stringing and oozing during printing. This combination makes it a common choice for functional brackets, mechanical parts, and items exposed to humidity or the outdoors.
Positioned between PLA and ABS, PETG captures much of ABS's durability and temperature resistance without the warping, fumes, or enclosure requirements, which is why it is frequently recommended as the next step up from PLA for parts that must endure real-world stress.