PETG Filament - Complete Guide
What is PETG?
PETG is a modified version of PET (the same plastic used in water bottles) with added glycol to improve printability and reduce brittleness. It offers excellent layer adhesion, chemical resistance, and impact strength while being easier to print than ABS.
PETG is the go-to material for functional parts that need durability, flexibility, and resistance to moisture and chemicals. It's widely used for mechanical parts, protective cases, outdoor items, and food-safe containers.
Typical Print Settings
| Setting | Recommended Range | Standard Value |
|---|---|---|
| Nozzle Temperature | 230-250°C | 240°C |
| Bed Temperature | 70-85°C | 80°C |
| Print Speed | 30-60 mm/s | 45 mm/s |
| Cooling | 30-50% | 40% |
| Retraction Distance | 1.0-2.0 mm (direct drive) 5-7 mm (bowden) |
1.5 mm / 6 mm |
| Layer Height | 0.12-0.28 mm | 0.20 mm |
See PETG print settings reference for detailed configuration options.
Strengths
- High strength and durability - Excellent impact resistance and toughness
- Chemical resistant - Withstands exposure to many chemicals and solvents
- Moisture resistant - Suitable for outdoor and humid environments
- Good layer adhesion - Layers bond very well, creating strong prints
- Flexible and impact resistant - Less brittle than PLA
- Heat resistant - Glass transition around 80°C, better than PLA
- Food safe - Many PETG formulations are food-safe when printed properly
- Clear variants available - Can achieve translucent or transparent prints
Weaknesses
- Very sticky - Adheres strongly to print bed, can be difficult to remove
- Prone to stringing - Requires careful retraction tuning
- Harder to print - More demanding than PLA
- Lower UV resistance - Not as UV-stable as ASA or ABS
- Hygroscopic - Absorbs moisture, requires drying before use
- Can ooze - Tends to ooze from nozzle during non-printing moves
- Surface quality - May show layer lines and imperfections more than PLA
Drying Guidance
PETG is highly hygroscopic and must be dried before printing. Wet PETG causes stringing, blobbing, poor layer adhesion, and brittle prints.
| Method | Temperature | Duration |
|---|---|---|
| Filament Dryer | 65-70°C | 4-6 hours |
| Food Dehydrator | 65°C | 4-6 hours |
| Oven (not recommended) | 65°C | 4-6 hours |
See PETG drying temperature guide for detailed instructions.
Storage Guidance
PETG requires proper storage to maintain print quality. It absorbs moisture faster than PLA and should always be kept in a dry environment.
- Store in airtight containers with desiccant immediately after opening
- Use vacuum-sealed bags for long-term storage
- Consider dry boxes with active drying for frequently used spools
- Monitor humidity levels (ideally below 20%)
- Re-dry if exposed to open air for more than a few days
Common Problems
Excessive Stringing
PETG strings more than PLA. Reduce temperature, increase retraction distance, and enable Z-hop. Dry the filament thoroughly.
Blobbing and Oozing
PETG tends to ooze from the nozzle. Adjust retraction, lower print temperature, or enable coasting.
Bed Adhesion Issues
PETG sticks very well. Use a release agent (glue stick or painter's tape) to prevent damage to print surfaces. Avoid printing directly on PEI.
Moisture Problems
Wet PETG produces poor prints with weak layers. Always dry filament before use.
Related Comparisons
- PLA vs PETG - Which material is right for your project?
- PETG vs ABS - Comparing strength and printability
Related Tools
- Spool Weight Calculator - Calculate remaining filament
- Print Cost Calculator - Estimate print costs