Most "bad filament" is actually wet filament. Nylon, polycarbonate and PETG absorb moisture from the air; even PLA degrades if stored badly. The fix is simple and cheap: dry it. Here's exactly how.
How to tell your filament is wet
- Bubbling or hissing from the nozzle
- Stringing and oozing that retraction tuning can't fix
- Matte, rough or blistered surfaces
- Brittle parts that snap instead of bending
- Poor layer adhesion and weak prints
Drying temperatures & times
| Material | Hygroscopic? | Dry before use | Recommended settings |
|---|---|---|---|
| PLA / PLA+ | Low | Not required | — |
| PETG | Medium | Recommended | 65 °C · 4 h |
| ABS / ASA | Low | Recommended | 80 °C · 4 h |
| PA (Nylon) / PA-CF | High | Mandatory | 80 °C · 8 h |
| PC | High | Mandatory | 100 °C · 6 h |
| TPU | Medium | Recommended | 70 °C · 4 h |
How to dry: 3 options
- Filament dryer box (best) — set temp and time, walk away. Great for PA/PC.
- Oven / food dehydrator — works, but verify temperature accuracy with a thermometer; most ovens overshoot.
- Print from a dry box — for long prints, feed directly from a dry box with desiccant to keep it dry during the job.
Storage: stop it getting wet again
Keep spools in sealed bags with desiccant, ideally in a dry box below 40% RH. Reuse the vacuum bag every VOXFIL spool ships with — it costs nothing and doubles spool life.
One more tip: if a spool prints poorly after months in storage, dry it before blaming the profile. Nine times out of ten, moisture is the culprit.