PETG — The Perfect Balance of Strength and Ease of Use
Glycol-modified PET
What Is PETG?
PETG is a modified version of PET (polyethylene terephthalate, commonly used in beverage bottles), with the addition of glycol (hence the “G”) to make it more suitable for FDM printing. It occupies the “sweet spot” in 3D printing materials — stronger and more durable than PLA, yet much easier to print than ABS.
Key Properties
- Print difficulty: Medium. PETG requires a bit more than PLA (mainly bed temperature), but it’s still manageable and an ideal step up after printing a few kilograms of PLA.
- Strong and tough: PETG’s layer adhesion is significantly stronger than PLA’s, producing parts that are overall more robust. It bends under stress rather than snapping like PLA.
- Good heat resistance: Heat deflection temperature of around 75-85°C, higher than PLA’s 50-60°C. Won’t soften or deform if left in a hot car in summer.
- Glossy surface finish: Printed parts naturally have a smooth, semi-transparent look that appears more premium than PLA.
- Downside: prone to stringing. PETG tends to ooze fine strings during travel moves, requiring retraction tuning to minimize them.
Recommended Print Settings
| Parameter | Recommended Range |
|---|---|
| Nozzle temperature | 230-245°C (start at 240°C) |
| Bed temperature | 75-85°C (heated bed required) |
| Print speed | 40-80 mm/s (slightly slower than PLA) |
| Layer height | 0.12-0.28 mm |
| Cooling fan | 30-50% (too much fan causes poor layer adhesion) |
| Retraction | Enable, distance 1-2 mm, speed 30-50 mm/s |
Best Uses
- Functional prototypes and mechanical parts
- Enclosures, brackets, storage bins (needing moderate strength)
- Outdoor items (UV resistant, impact resistant)
- Food contact containers (use food-grade PETG and maintain hygiene during printing)
Recommended Brands
- Polymaker PolyLite PETG ($8-$13/kg): One of the most consistently reliable PETG brands, smooth printing, wide color selection.
- Bambu Lab PETG-HF ($10-$14/kg): Optimized for high-speed printing, achieving good surface quality at 300 mm/s.
- eSun PETG ($6-$9/kg): Great value, performs well once retraction parameters are dialed in.
- Overture PETG ($7-$10/kg): Popular brand in the US market, consistent quality, blue and transparent colors particularly well-liked.
Important Notes
PETG is sensitive to bed adhesion. A PEI-coated sheet or blue painter’s tape is recommended as the print surface. If using a glass bed, apply a thin layer of PVA glue as a release agent — PETG adheres so strongly to glass that it can chip the glass surface when removed.
Drying Guide
PETG absorbs moisture more readily than PLA. Drying conditions: 65-70°C for 6-8 hours, or store in a dry box during use. Moisture-laden PETG will show surface bubbling during printing and suffer from reduced strength — keep it dry.