PETG stringing: causes and fixes

PETG strings most often because the filament is wet. Dry the spool first (55–65 °C for 6–8 hours), then lower the nozzle temperature by 5–10 °C, and only then adjust retraction.

Updated: November 2026

Some stringing is normal with PETG. The goal is thin wisps you can wipe off with a finger. Work through this list in order and change one thing at a time:

1. Dry the filament.
2. Lower the nozzle temperature.
3. Set retraction for your extruder type (direct drive or Bowden).
4. Speed up travel moves.
5. Turn on wipe and avoid crossing walls.
6. Clean the nozzle.

How do I know my PETG is wet?

Wet PETG pops or hisses while printing, leaves lots of fine strings, and shows small bubbles and pits on the surface. When you see that, leave the settings alone and dry the spool first.

PETG absorbs moisture from the air. According to Bambu Lab, freshly dried filament in a typical room (around 55% humidity) takes up enough water to hurt print quality within 2 to 12 hours. After drying, keep the spool in a sealed box with silica gel.

At what temperature and for how long should I dry PETG?

Dry PETG at 55–65 °C for 6–8 hours. If the spool label gives its own values, use those.

Source: Prusa Knowledge Base (Drying filament), Bambu Lab Wiki (Dry filament, Appendix I).

A kitchen oven doesn't measure temperature accurately. Check it with a thermometer or use a filament dryer such as the PolyDryer.

What nozzle temperature stops PETG stringing?

Start in the lower half of the range printed on the spool and go down in 5 °C steps until the strings thin out. When layers stop bonding well, go back one step.

Prusa recommends 240 °C for PETG (230 °C for the first layer). The Bambu Lab PETG HF profile uses 245 °C (230 °C for the first layer).

A temperature tower is the quickest way to find it. In Bambu Studio and OrcaSlicer it is under Calibration → Temperature. Temperatures for other materials are in our filament temperature chart.

What retraction is right for direct drive and Bowden?

Direct drive needs only a short retraction, around 0.8 mm. Bowden needs more, usually 3–6 mm, because the filament runs to the nozzle through a long tube.

Direct drive printers include the Bambu Lab A1, P1S and X1C and the Prusa MK4 and Core One. The Prusa MINI and the original Creality Ender-3, Ender-3 Pro and Ender-3 V2 use Bowden.

Increase retraction in small steps: 0.2 mm on direct drive, 0.5 mm on Bowden. For its direct drive MK3 and MK2.5, Prusa recommends no more than 2 mm.

What starting values should I use?

For standard PETG and a 0.4 mm nozzle, these are good starting values. If the spool label gives a higher range (Bambu Lab PETG Basic says 240–270 °C), start at its lower end.

Source: default profiles in Bambu Studio (X1C, P1S: 0.8 mm, 30 mm/s) and PrusaSlicer (MK4: 0.8 mm, 35 mm/s; MINI: 3.2 mm, 45 mm/s for PETG; PETG lift 0.15–0.2 mm), Creality (PETG on the Ender-3: around 6 mm, 40 mm/s max).

Do faster travel moves help?

Yes. The less time the nozzle spends over empty space, the less plastic oozes out. Set travel to at least 150 mm/s if your printer can handle it. Bambu Lab profiles already travel much faster, so there is nothing to change there.

The minimum travel distance that triggers a retraction matters too. Bambu Studio defaults to 1 mm. Prusa notes that a higher value saves print time but adds stringing.

What do wipe and avoid crossing walls do?

Wipe moves the nozzle along the last printed line while retracting, so any plastic that oozes out stays on the part, not in the air. Avoid crossing walls routes travel inside the model, so any string that does form ends up in the infill where you can't see it.

Keep Z hop low. According to Prusa, a lower lift reduces stringing. With no lift at all, though, the nozzle can catch the print.

Where are these settings in Bambu Studio, OrcaSlicer and PrusaSlicer?

Retraction is in the printer settings, but it is better to change it for PETG only, in the filament settings. Some of these settings only appear in advanced mode (Advanced in Bambu Studio, Expert in PrusaSlicer). The names below are from the English interface:

Bambu Studio and OrcaSlicer: retraction is in the printer settings on the Extruder tab, and per filament in the filament settings on the Setting Overrides tab. Avoid crossing wall is under Quality → Advanced in Bambu Studio and Quality → Walls and surfaces in Orca.

PrusaSlicer: retraction is in Printer Settings → Extruder 1, and per filament in Filament Settings → Filament Overrides. Avoid crossing perimeters is in Print Settings → Layers and perimeters. In Cura, look for Retraction Distance, Retraction Speed and Combing Mode.

Bambu Studio and OrcaSlicer also have a retraction test in the Calibration menu, so you can pick the value from a print instead of guessing.

What if the strings are still there?

Clean the nozzle. Prusa points out that after long runs of one material, such as PETG, a thin layer of plastic builds up in the nozzle and pulls strings. If that doesn't help, try another spool to rule out moisture, and check the hotend.

FAQ

Is some stringing normal with PETG?

Yes. Prusa describes PETG as prone to stringing. Thin strings you can wipe off are normal. Thick strands and blobs are not.

Why does PETG string more than PLA?

PETG prints hotter and is stickier when molten. During travel it oozes out of the nozzle more easily and stretches between parts of the model.

Do I need to dry a new spool?

Bambu Lab recommends drying PETG before use. If a new spool strings, start by drying it.

How do I remove strings from a finished print?

Pass a heat gun set to around 200 °C over them for one or two seconds. Don't heat any longer or the part may deform. This is the method Prusa recommends.

Will a longer retraction help?

Only up to a point. If the filament is wet or the nozzle too hot, longer retraction won't remove the strings. Change it only after drying and lowering the temperature.

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