Quick answer
PETG stringing is caused mostly by moisture in the filament, a nozzle temperature that’s too high, and insufficient retraction. Dry the spool at 60-65C for 6-8 hours, lower the nozzle temperature in 5C steps, tune retraction, and turn Z-hop off. Working through these in order clears stringing in nearly all cases.
Why PETG strings more than PLA
PETG doesn’t snap cleanly the way PLA does - it stays soft and stretchy as the nozzle moves, so it tends to drag fine threads across the print unless temperature, moisture, and retraction are dialed in. That’s why the fix is rarely a single setting; it’s a short sequence of adjustments.
The PETG anti-stringing checklist
1. Dry the filament first
PETG absorbs moisture faster than most people expect - even a weekend on the shelf can be enough. When wet PETG hits the nozzle, trapped water flashes to steam and pushes molten plastic out during travel moves. Dry the spool at 60-65C for 6-8 hours before troubleshooting anything else.
2. Lower the nozzle temperature
Too hot and PETG stays runny and oozes. Drop the nozzle temperature in 5C increments (e.g. 250 → 245 → 240) and watch where stringing improves without hurting layer adhesion.
3. Tune retraction
Insufficient retraction leaves filament free to ooze between moves. Increase retraction distance gradually until strings disappear. On direct-drive Bambu machines the needed distance is small, so step up carefully.
4. Turn Z-hop OFF
For PETG, Z-hop often makes stringing worse - lifting the nozzle pulls the softened material up and out. Disable it.
5. Slow travel and enable wiping
Faster travel gives oozing material more distance to stretch into a string. Lower travel speed slightly and enable a wipe/coast move so the nozzle cleans itself on the way out.
Frequently asked questions
What temperature should I dry PETG at?
60-65C for 6-8 hours in a filament dryer or oven.
Why is my PETG stringing even with retraction tuned?
Almost always moisture. Dry the spool before assuming the settings are wrong.
Should I use Z-hop with PETG?
Generally no - it tends to increase stringing. Leave it off unless you have a specific clearance reason.
Is some PETG stringing normal?
Light wisps that brush off easily are common and usually acceptable; heavy webbing means moisture or temperature is off.