Wet filament produces a range of print quality issues caused by moisture absorbed from the air. Symptoms include popping or hissing sounds during extrusion, rough and bubbly surface texture, excessive stringing, and poor layer adhesion.
Common Causes
- Filament stored without desiccant — Hygroscopic materials absorb ambient humidity over time
- Prolonged exposure to air — Leaving filament on the printer in humid conditions degrades quality
- High-humidity environment — Nylon, PETG, TPU, and PVA are especially sensitive to moisture
- Sealed bags opened too early — Factory-dried filament absorbs moisture within hours in humid climates
- Reusing old filament — Material stored improperly for weeks or months may be saturated
Recommended Fixes
- Dry filament in a food dehydrator or filament dryer at recommended temperatures:
- PLA: 45°C for 4-6 hours
- PETG: 65°C for 4-6 hours
- Nylon: 70°C for 12+ hours
- TPU: 55°C for 4-6 hours
- Store filament in sealed containers or vacuum bags with silica gel desiccant
- Use a dry box that feeds filament directly to the printer during printing
- Print a temperature tower after drying to verify improved extrusion quality
- Replace severely degraded filament that does not improve after thorough drying