Strings and cobwebs appear between parts (stringing)
Stringing occurs when the nozzle oozes during travel moves. It is tackled with retraction, lower temperature and, often, drying the filament.
What the failure looks like
Fine strings appear between towers, holes or separate parts when removing the print. Almost always in PETG; in PLA only if something is wrong.
Causes, most likely first
- 01
Damp filament
It is the most underestimated cause, especially with PETG and nylon. Water evaporates in the nozzle and drags plastic along.
- 02
Insufficient retraction
Too little distance or speed.
- 03
High temperature
Plastic that is too liquid oozes on its own.
- 04
Slow travel moves
The longer it takes to cross, the more time it has to ooze.
Step-by-step fix
1. Dry the filament
PETG: 65 °C for 4-6 h. PLA: 45-50 °C, 4 h. Nylon: 70 °C, 8-12 h. A food dehydrator works perfectly.
2. Print a temperature tower
Find the lowest temperature that still gives good layer adhesion.
3. Adjust retraction
Direct drive: 0,5-1,5 mm at 25-40 mm/s. Bowden: 4-7 mm at 30-45 mm/s.
4. Increase travel speed
150-250 mm/s if the hardware can handle it.
5. Enable 'avoid crossing perimeters'
And wipe while retracting.
| Material | Typical temperature | Direct drive retraction | Tendency to string |
|---|---|---|---|
| PLA | 195-215 °C | 0,6-1 mm | Low |
| PETG | 230-245 °C | 1-1,5 mm | High |
| ABS | 240-255 °C | 0,8-1,2 mm | Medium |
| TPU | 215-230 °C | 0-0,5 mm | Very high |
So it doesn't happen again
- Store filament in a bag with silica gel; PETG and nylon absorb moisture within days.
- Keep a filament dryer if you print technical materials frequently.
Related questions
Can strings be removed with a heat gun?
Yes, a quick pass from a distance removes fine strings, but it is a post-processing workaround: if you have to do it every time, adjust your profile.
Why does TPU always string?
It is elastic: retraction does not pull the material in the same way. It is reduced with low temperature, consistent speed and minimal retraction.
Keep reading
What if it isn't worth your time?
Sometimes the part is more urgent than the learning curve. We're a workshop in Viladecavalls: send us the file and we'll print it with the right material and settings.
Still not working?
Tell Marco which printer and material you use and he'll tell you what to change.
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