Polyethylene terephthalate (PET) is the most commonly used plastic in the world. You can find the polymer almost everywhere you look, from your water bottle to clothing fibers, even in your food containers. PET is also used in thermoforming processes and can be combined with glass fiber to create engineering resins. Basically, thousands of consumer products, foods, and beverages are delivered and packaged within this material. Unfortunately, it‘s even floating in our oceans.
On the 3D printing side of things, there’s PETG, which is is a modified version of PET. The ‘G’ stands for “glycol-modified”, which is added to the material composition during polymerization. The result is a filament that is clearer, less brittle, and easier to use than its base form of PET. The molecular structure is irregular; the resin is clear and amorphous with a glass transition temperature of 88 C (190 F). If you’re into chemistry, this material is known as Polyethylene Terephthalateco-1, 4-cylclohexylenedimethylene terephthalate (try saying that mouthful three times quickly…).
It’s also worth letting Polyethylene coTrimethylene Terephthalate (PETT) make a cameo in this guide. PETT, as you can probably tell, is another variant of PET. It’s slightly more rigid than PETG, and is popular for being transparent.
Learn more about other filament types: 3D Printer Filament – 25 Best Types & Comparison Charts