How to Fix Stringing in 3D Printing
Stringing is the #1 complaint on r/3Dprinting. This guide walks you through every cause and fix — retraction settings, temperature, travel speed, and slicer tricks — so you can eliminate those annoying hair-like threads for good.
Stringing (also called "hairy prints" or "cobwebbing") occurs when molten plastic oozes out of the nozzle as it travels between parts of the print. The nozzle moves through open air, drags a thin thread of plastic behind it, and the result looks like a spider web.
There are three main causes:
- Temperature is too high — hotter plastic is runnier and oozes more
- Retraction is too weak — the slicer isn't pulling filament back far enough during travel moves
- Travel speed is too slow — the nozzle spends too long in open air
Step 1: Lower Your Temperature
This is the single most effective fix. Drop your nozzle temperature by 5°C at a time and test.
| Material | Typical Range | Start Here for Stringing |
|---|---|---|
| PLA | 190–220°C | Try 195–200°C |
| PETG | 230–250°C | Try 235–240°C |
| ABS | 230–250°C | Try 235°C |
| TPU | 210–230°C | Try 215°C |
Too cold causes under-extrusion, so find the sweet spot — usually 5–10°C above the minimum the material flows cleanly.
Step 2: Tune Retraction
Retraction pulls filament back into the nozzle before a travel move, reducing pressure so plastic doesn't ooze out.
Direct Drive Printers (Bambu, Prusa MK4, Ender 3 with direct drive)
- Retraction distance: 0.5–1.5mm
- Retraction speed: 25–45mm/s
Bowden Printers (stock Ender 3, Anycubic Kobra)
- Retraction distance: 4–7mm
- Retraction speed: 40–60mm/s
Warning: Too much retraction causes clogs and grinding. Don't go above 2mm on direct drive or 7mm on Bowden.
How to test retraction
Print a retraction test tower (search "retraction tower" on Printables). It prints the same shape at increasing retraction distances so you can see exactly where stringing stops.
Step 3: Increase Travel Speed
The faster the nozzle moves between parts, the less time it has to ooze. Set travel speed to at least 150mm/s — 200mm/s is better if your printer can handle it.
In Cura: Travel Speed In PrusaSlicer/OrcaSlicer: Travel Speed
Step 4: Enable "Avoid Crossing Perimeters" / "Combing"
Most slicers have a setting that routes travel moves over already-printed areas instead of open air. This doesn't eliminate stringing but hides it inside the part.
- Cura: Enable "Combing Mode" → set to "Within Infill" or "All"
- PrusaSlicer: Enable "Avoid crossing perimeters"
- OrcaSlicer/Bambu Studio: Enable "Avoid crossing wall"
Step 5: Material-Specific Tips
PETG strings more than any other common material. It's hygroscopic and sticky. In addition to the steps above:
- Dry your PETG before printing (4 hrs at 65°C)
- Use a lower temperature than you think (235°C is often enough)
- Enable "Wipe while retracting" in your slicer
ABS strings less than PETG but is sensitive to temperature fluctuations. An enclosure helps maintain consistent temps and reduces stringing.
TPU is the hardest to tune for stringing. Because it's flexible, retraction often causes jams. Many users print TPU at 0mm retraction and rely entirely on temperature and travel speed.
Quick Checklist
- Lower temperature by 5–10°C
- Increase retraction distance (within safe limits)
- Increase retraction speed
- Set travel speed to 150–200mm/s
- Enable combing/avoid crossing perimeters
- Dry filament if it's been open for more than a few days
- Print a retraction tower to dial in the exact value
Follow these steps in order and most stringing problems resolve within 2–3 test prints.