Filament Storage and Drying: A Practical Guide
Why moisture matters
Water trapped in filament flashes to steam at the nozzle. You will hear it pop, see steam, and the resulting print has reduced layer adhesion, stringing and a dull surface. Nylon and TPU show this fastest; PLA and PETG show it after weeks of exposure.
Which materials need drying most
| Material | Moisture sensitivity |
|---|---|
| Nylon | Extreme. Dry every time. |
| TPU | High. Dry weekly during use. |
| PETG | Medium. Dry if it has been open a month. |
| ABS / ASA | Medium. |
| PLA | Low to medium. Still affected after months open. |
Signs of wet filament
- Popping or cracking sounds at the nozzle
- Visible steam at the hotend
- Stringing that was not there with the same spool fresh
- Dull, rough surface finish
- Brittle prints that snap at layer lines
Storage between prints
- Original bag plus silica gel, resealed (fine for weeks)
- Sealed dry box with bulk silica (fine for months)
- Active dehumidifier dry box for long-term archival
- Avoid leaving spools on the printer for days in a humid room
Drying methods
- Filament dryer: cleanest option, controllable, prints from the dryer
- Food dehydrator: works, often cheaper
- Oven: set 60 to 70 C for PLA, 70 to 80 C for PETG, 80 to 90 C for nylon and TPU. Check with an oven thermometer; many ovens overshoot
- Microwave: do not use this
Dry times to start with
| Material | Temp | Time |
|---|---|---|
| PLA | 45 to 55 C | 4 to 6 hours |
| PETG | 65 C | 4 to 6 hours |
| ABS / ASA | 75 C | 4 to 6 hours |
| TPU | 50 C | 6 to 8 hours |
| Nylon | 80 C | 8 to 12 hours |
What we ship with
Every Siddament spool ships with silica gel inside a resealable bag. That bag is the simplest dry-box you have. Keep it.