Guide
How to dry filament (and know when you need to)
Here's the diagnosis most beginners never get told: when a printer that worked fine starts making rough, stringy, crackling prints, the filament got wet. Plastic filament absorbs moisture straight from the air — and at printing temperature that moisture boils, steaming tiny bubbles through your print. It looks exactly like a broken printer. It's a $0 fix.
Drying cheat sheet
| Filament | Temperature | Time | How often it's needed |
|---|---|---|---|
| PLA | 45 °C | 4–6 h | Rarely — only after months in open air |
| PETG | 55 °C | 6 h | Often — absorbs moisture within days |
| TPU | 55 °C | 6–8 h | Almost always — dry before every big print |
| ASA / ABS | 60 °C | 4–6 h | Sometimes |
| Nylon | 70 °C | 8–12 h | Always — the thirstiest filament there is |
Golden rule: never dry a filament hotter than it can bear — PLA especially fuses into a useless brick above ~50 °C. When unsure, go lower and longer.
What to dry it with
A filament dryer is the purpose-built answer: a small heated box that holds a spool or two, keeps an exact temperature, and can feed the printer while drying. If you print PETG or TPU regularly, it pays for itself in un-ruined prints.
A food dehydrator is the classic budget hack — accurate low temperatures by design; many makers cut the trays out and drop spools in whole.
Your kitchen oven is the risky option. Most home ovens can't hold 50 °C honestly — they cycle far above it, and the difference between "dried" and "fused into modern art" is about 15 degrees. Verify with a real thermometer or don't.
Keeping it dry (the lazy way that works)
Drying is the cure; storage is the vaccine. Every spool not in use goes in an airtight bag or box with silica desiccant — the packet it shipped with counts. Rechargeable silica beads (the color-changing kind) can be revived in a dryer or oven forever. That's the whole system: dry when symptomatic, store sealed, recharge the beads. Your prints stay consistent, and you stop blaming the printer for the weather.
Not sure which filament you should even be printing? Take theFilament Picker— it flags the moisture-sensitive ones before you buy.
Common questions
How do I know my filament is wet?
Listen and look: faint popping or crackling at the nozzle, steam wisps, rough or fuzzy surfaces, sudden heavy stringing, and weak parts that snap along layers. If a filament printed beautifully a month ago and looks terrible today with the same settings, it's wet — not your printer.
Can I dry filament in a kitchen oven?
Risky but possible if your oven is accurate at low temperatures. Most home ovens overshoot badly at 45–60 °C, and an overshoot melts the spool into a block. If you try: preheat, verify with a separate thermometer, and never trust the dial. A food dehydrator or purpose-built filament dryer is far safer.
Does drying damage filament?
Not at the right temperature — drying is gentle and repeatable. What damages filament is exceeding its softening point: dry PLA above ~50 °C and the spool can fuse. Stay at the recommended temperature for the material and you can dry the same spool dozens of times.
How should I store filament so it stays dry?
Airtight box or bag with desiccant beads, out of sunlight. Cheapest version that actually works: a zip bag with the silica packet the spool shipped with. Nicer version: a sealed cereal-style container with rechargeable silica. Spools you're actively using can live on the printer for days (PLA) — just not weeks.