Signs your filament is wet
Popping or hissing at the nozzle, steam, heavy stringing, rough or bubbly surfaces, weak brittle parts and filament that snaps easily (especially PLA) all point to moisture. Nylon, TPU, PVA and PC can absorb enough water to ruin prints within a day in humid air.
How to dry filament
A dedicated filament dryer is the easiest and safest. A convection oven works if it holds low temperatures accurately — check with a separate thermometer, because many ovens overshoot by 10–20 °C, which can fuse a PLA spool. Food dehydrators work well for PLA, PETG and TPU but rarely reach the 70–80 °C nylon needs. After drying, store spools in a sealed box with silica gel below ~20% humidity, or print straight from the dryer.
More detail in our guide: how to dry filament.
FAQ
What temperature should I dry PLA at?
45–50 °C for 4–6 hours. Going above about 55 °C can soften the filament and make it stick to itself on the spool.
How long should I dry PETG?
4–6 hours at 60–65 °C.
Can I dry filament in a regular oven?
Yes, if it holds low temperatures accurately. Verify with a separate thermometer and never leave plastic spools unattended in an oven.
Does new filament need drying?
Often not, if it arrives vacuum-sealed with desiccant. Nylon, TPU and PVA frequently benefit from drying even when new.
Recommended gear
- Filament dryer — Dries while you print. Check max temperature (≥70 °C) if you print nylon.
- Airtight dry box + silica gel — Cheap way to keep dried spools dry; add a hygrometer.
- Mini hygrometers — Know the humidity inside your storage box.
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