Why PETG Deserves Attention
PETG sits between PLA and ABS in the material spectrum. It's nearly as easy to print as PLA, but significantly stronger, more temperature-resistant, and less brittle. It doesn't warp like ABS, doesn't need an enclosure, and handles impacts better than PLA. For functional prints — phone mounts, drone parts, tool handles, enclosures — PETG is often the best choice.
But it has quirks. PETG stringing is notorious. It's stickier than PLA, meaning nozzle ooze and wispy strings between detached parts. Over-extrude even slightly and you get glossy, bulging surfaces. Under-extrude and layer lines gape open. The good news: once you dial in PETG-specific settings, it becomes one of the most reliable materials in your arsenal.
Temperature Settings
Hotend
Most PETG prints best between 230–250°C. Start at 240°C and adjust from there. Lower temps (230°C) reduce stringing but may cause under-extrusion on fast prints. Higher temps (250°C) improve layer bonding and flow but increase ooze. If your printer has a temperature tower calibration feature, use it — 5°C increments between 230 and 250 will reveal your filament's sweet spot.
Bed
70–80°C bed temperature. PETG adheres well to PEI, textured steel, and even plain glass with a light glue stick application. Unlike PLA, you don't need aggressive adhesion aids — PETG naturally sticks well to warm surfaces. The problem is the opposite: PETG can bond so strongly to smooth surfaces that removing the print damages the plate. Textured PEI is ideal because it gives grip while allowing clean removal.
Stringing: PETG's Biggest Challenge
Stringing happens when the nozzle oozes filament during travel moves between separate parts of the print. PETG's lower viscosity means it flows more readily at printing temperature, creating those thin plastic spider-web strings.
Retraction Settings
- Direct-drive extruder: 0.4–0.8 mm retraction distance, 25–40 mm/s retraction speed
- Bowden extruder: 2.0–4.0 mm retraction distance, 25–40 mm/s retraction speed
- Start conservative and increase until strings disappear. Over-retracting causes under-extrusion at the start of each new segment.
Additional Anti-Stringing Measures
- Wipe before retraction: The nozzle wipes across the last printed point, smoothing any residual filament before pulling away. Available in most slicers.
- Coasting: Stops extrusion slightly before the end of a segment, letting residual pressure empty naturally. Reduces ooze at segment boundaries.
- Lower travel speed threshold: Sometimes reducing travel speed paradoxically reduces stringing because the filament has less momentum to drag along.
Cooling
PETG needs less cooling than PLA. Too much fan causes poor layer bonding and delamination on vertical walls. The standard approach:
- First 3–4 layers: fan off or minimum (10–20%)
- After that: 30–50% fan for overhangs and bridges, 20–30% for general printing
- Never run PETG at 100% fan — you'll get weak, delaminating prints
For purely structural parts where strength matters more than appearance, leave the fan at 0% after the first few layers. The surfaces will be slightly rougher but significantly stronger.
Print Speed
PETG likes moderate speeds. 40–60 mm/s for outer walls, 80–120 mm/s for inner walls and infill. Pushing past 150 mm/s with a standard 0.4 mm nozzle often leads to under-extrusion and surface artifacts. If you need speed, use a 0.6 mm nozzle — PETG flows through it easily at 200 mm/s while maintaining quality.
Storage and Moisture
PETG absorbs moisture faster than PLA. Wet PETG pops, sputters, and produces cloudy, weak prints with tiny bubbles in the surface. Keep your spools in a dry environment — a filament drying box is the simplest solution, keeping filament dry and ready to print. If you hear popping sounds during printing, dry the spool at 65°C for 4–6 hours before continuing.
With proper settings and dry filament, PETG produces tough, functional prints that outlast PLA in real-world use. Explore our PETG filament options to find the right spool for your next project.