The short answer
Stringing happens when melted plastic leaks from the nozzle while it moves between parts of a print. The usual fixes, easiest first: dry your filament, lower the nozzle temperature a little, and adjust retraction in your slicer.
In this post
What does 3D printer stringing look like?
Thin, hair-like strands stretch between parts of your print, like a cobweb across the gaps. You'll see it most on prints with separate towers or spikes, where the nozzle has to cross open air.
Why does my 3D printer string?
When the nozzle travels from one part of a print to another, it's still hot and full of melted plastic. A little leaks out on the way and leaves a thread behind. Your printer fights this with retraction: it pulls the filament back a few millimeters before each move so less plastic can leak. Stringing means some part of that balance is off.
The six fixes, easiest first:
- Step 1:
Dry your filament
Wet filament steams and pushes out extra plastic.
- Step 2:
Lower the nozzle temperature
Drop 5°C at a time, inside the spool's range.
- Step 3:
Adjust retraction
One setting at a time, with a test print.
- Step 4:
Shorten the trip
Travel settings that avoid open air.
- Step 5:
Check the nozzle
Clean the outside, or replace a worn one.
- Step 6:
Expect a little with some materials
PETG and flexible filaments string more.
Fix 1: Dry your filament
Filament soaks up moisture from the air. Wet filament turns to steam in the hot nozzle, which pushes out extra plastic, and it often pops or crackles as it prints. If your strings come with a hiss or a rough surface, start here.
- Dry the spool in a filament dryer, or an oven that holds a low temperature, at the setting the filament maker recommends.
- Store spools sealed with a desiccant pack. That's what those silica packets that come with a new printer are for, as we showed in our H2C setup video (opens in a new tab).
PETG, TPU, and nylon pick up moisture faster than PLA, so they string more when they're wet.
Watch: why new printers come with silica packets (opens in a new tab), a 30-second Short from our setup.
Fix 2: Lower the nozzle temperature
Hotter plastic runs more freely, so it leaks more. Drop the nozzle temperature by 5°C and print again. Stay inside the range printed on the spool. Too cool and your layers won't bond.
To find the sweet spot in one print, search your slicer or a model site for a temperature tower. It prints one section at each temperature so you can compare them side by side.
Fix 3: Adjust retraction
Retraction has two main settings in your slicer:
- Distance: how far the filament pulls back. Printers with the motor right above the nozzle (direct drive) usually need less, often under 2 mm. Printers that push filament through a long tube (Bowden) usually need more.
- Speed: how fast it pulls back.
Start from your slicer's profile for your exact printer and filament. Change one setting at a time, in small steps, and print a retraction test model between changes. Too much retraction can cause gaps or clogs, so go slowly.
Fix 4: Shorten the trip
Fewer and shorter trips across open air mean fewer strings.
- Turn on the setting that keeps the nozzle over the print while it travels. Slicers name it differently: "avoid crossing walls," "avoid crossing perimeters," or "combing."
- Raise the travel speed so the nozzle spends less time over the gaps.
- Turn on "wipe" if your slicer has it. The nozzle wipes across the part before it moves.
Fix 5: Check the nozzle
A nozzle with plastic baked onto the outside, or a partial clog, can drip and drag strings. Heat it up and clean the outside following your printer's guide. A worn nozzle is a common, cheap part to replace.
Fix 6: Expect a little with some materials
PETG and flexible filaments string more than PLA, even when everything is set up well. A few fine wisps on a PETG part are normal.
Cleaning up the strings you already have
Fine wisps snap off with your fingers or a pair of flush cutters. Some makers wave a heat gun over the part for a second to shrink them. That's a job for an adult, and keep moving so the part itself doesn't soften.
Quick checklist
Printable checklist
Stop 3D printer stringing
- Dry the filament.
- Drop the nozzle temperature 5°C at a time, within the spool's range.
- Tune retraction one setting at a time, with a test print.
- Turn on the travel settings that avoid open air.
- Clean or replace the nozzle.
From Layer Notes at z-access.com
More fixes
If your print comes loose before it ever gets to stringing, read why the first layer won't stick (opens in a new tab). We post quick fixes like these on YouTube (opens in a new tab), Facebook (opens in a new tab), and TikTok (opens in a new tab).
Questions makers ask
Why is my PETG stringing so much?
PETG strings more than PLA by nature, and it picks up moisture quickly. Dry it, print toward the low end of its temperature range, and use the travel settings above. Expect a few fine wisps.
Is stringing bad for my printer?
Usually it only affects how the print looks. Heavy stringing that comes with popping or a rough surface often means wet filament, which can also weaken prints.
What retraction settings should I use?
Start with your slicer's built-in profile for your printer and filament. Adjust in small steps and print a retraction test after each change.
Can wet filament cause stringing?
Yes. Moisture turns to steam in the nozzle and pushes out extra plastic. It's one of the most common causes, and one of the easiest to fix.
