Filament Drying Guide
Complete drying reference for 21 filament materials — exact temperatures, times, hygroscopic ratings, and storage recommendations. Cross-referenced against 25+ manufacturer datasheets.
Drying Temperature & Time Reference
| Material | Temp °C | Hours | Max Safe °C | Drying | Hygroscopic | Storage RH | Notes |
|---|---|---|---|---|---|---|---|
| PLA | 40–50 | 4–6 | 55 | Recommended | Low | <40% | PLA is forgiving but benefits from drying in humid climates. Start at 45°C.⚠ Never exceed 55°C — PLA's glass transition is ~60°C and filament loops will fuse on the spool. |
| PLA+ | 45–50 | 4–6 | 55 | Recommended | Low | <40% | Same as PLA. eSUN recommends 45–50°C for 4–6 hours for their PLA+. |
| Silk PLA | 40–50 | 4–6 | 50 | Recommended | Low-Medium | <35% | Moisture ruins the glossy finish. Dry to preserve the sheen that makes silk PLA special. |
| Matte PLA | 40–50 | 4–6 | 55 | Recommended | Low | <40% | Behaves identically to standard PLA for drying. |
| Wood PLA | 40–50 | 4–6 | 50 | Recommended | Medium | <35% | Wood particles absorb extra moisture and can swell, causing nozzle clogs.⚠ Use lower end (40–45°C) for lighter wood colors — heat darkens the wood particles. |
| PVB | 50–60 | 8–12 | 60 | Required | Medium-High | <30% | More hygroscopic than PLA (Polymaker). Must be dry for smooth IPA vapor finishing. |
| PETG | 55–65 | 4–8 | 70 | Recommended | Medium | <30% | Wet PETG is the #1 cause of excessive stringing. Dry if opened >1 week. |
| PETG-CF | 60–70 | 6–8 | 75 | Recommended | Medium | <30% | CF creates micro-channels that can trap moisture. Dry slightly longer than plain PETG. |
| PCTG | 60–70 | 4–8 | 75 | Recommended | Medium | <30% | Less moisture-sensitive than PETG. Better for long-term storage. |
| TPU / TPE | 50–60 | 4–8 | 65 | Required | High | <20% | Wet TPU loses flexibility, feels tacky, and prints terribly. Re-absorbs moisture within hours.⚠ Softer TPU (Shore 85A and below) should stay at 45–50°C to avoid deformation. Sources disagree on max temp (40–70°C range). |
| ABS | 65–80 | 4–6 | 85 | Recommended | Low-Medium | <40% | Less hygroscopic than PETG. Benefits from drying in humid environments. |
| ASA | 65–75 | 4–6 | 85 | Recommended | Low-Medium | <40% | Similar to ABS. Dry before printing for best UV resistance properties. |
| HIPS | 60–65 | 2–6 | 75 | Optional | Low | <40% | Least demanding to dry. Primarily used as dissolvable support (limonene). |
| PLA-CF | 45–55 | 6–8 | 55 | Recommended | Low-Medium | <35% | CF micro-channels absorb slightly more moisture than plain PLA. Same temp limits as PLA. |
| Nylon PA6 | 80–90 | 8–12 | 100 | Required | Very High | <15% | The most hygroscopic common filament. Can absorb up to 3% of its weight. Print from a dry box.⚠ Saturated PA6 may need 24+ hours. Over-dried nylon can be brittle — a tiny amount of moisture is needed for optimal printability (3DXTECH). |
| Nylon PA12 | 80 | 6–8 | 90 | Required | High | <20% | Less hygroscopic than PA6 (absorbs ~0.5%). Easier nylon to work with. Still needs drying. |
| CF Nylon | 80–100 | 8–12 | 100 | Required | Very High | <15% | Carbon fiber does not reduce nylon's hygroscopic behavior. Dry before every print session. |
| PC | 80–120 | 4–8 | 120 | Required | High | <20% | PC blends (Polymaker): 75–85°C. Pure PC (3DXTECH): 100–120°C. Formulation matters.⚠ Sources disagree: Polymaker says 75°C/6–12hrs, 3DXTECH says 120°C/4hrs. Match to your specific PC formulation. |
| PVA | 45–55 | 8–12 | 60 | Required | Very High | <20% | Water-soluble support material. Extremely hygroscopic — will dissolve in high humidity.⚠ PVA softens at low temps. Use static/gentle drying mode only. Never use high-temp drying (Bambu Lab warning). |
| PP | 55–70 | 4–8 | 80 | Recommended | Low-Medium | <40% | Some formulations don't need drying (Fillamentum). Others do (Polymaker, Raise3D). Dry if unsealed. |
| PEEK | 120–150 | 4–6 | 160 | Required | Medium-High | <20% | Requires industrial drying equipment. Consumer dryers cannot reach these temps.⚠ Moisture must be below 0.02% to prevent foamy extrusion at 380–420°C print temps. Use forced-air convection oven. |
Drying Methods Compared
Dedicated Filament Dryer
Cannot reach temps for Nylon, PC, PEEK. Check your unit's max temp. Sunlu S2, eSUN eBox, Sovol SH02 are popular options.
Food Dehydrator
Most top out at 70°C. Temperature accuracy varies — verify with a thermometer. Remove trays to fit spool.
Convection Oven
Consumer ovens overshoot 5–20°C — use an oven thermometer. Keep spool away from heating elements. Never use for PLA (easy to overshoot).
Printer Heatbed (Enclosed)
Works in a pinch. Place spool on heated bed inside enclosure. Flip halfway. Bambu recommends 90°C/10hrs for engineering materials.
Important Warnings
- Never use a microwave. Uneven heating will destroy the filament.
- Kitchen ovens have poor temperature uniformity. Always verify with an oven thermometer — consumer ovens can overshoot by 5–20°C.
- Most plastic spools soften at ~70°C. If drying above 70°C, use filament on cardboard masters or remove from spool.
- Seal immediately after drying. Dried filament re-absorbs moisture within hours in humid conditions. Use airtight storage with desiccant.
- Hydrolysis is irreversible. Prolonged moisture exposure causes chemical degradation (broken polymer chains). Drying removes water but cannot repair this damage. Severely degraded filament should be discarded.
How to Tell If Your Filament Is Wet
Popping / Crackling
Audible sounds from the hotend as moisture turns to steam and escapes through the nozzle.
Surface Bubbles
Visible bubbles and pitting on the print surface from steam escaping the extrusion.
Excessive Stringing
Thin strings between features — steam creates internal pressure that pushes filament out.
Poor Layer Adhesion
Layers delaminate or separate easily. Steam disrupts the bond between layers.
Surface Roughness
Pitted, cratered, or foamy texture instead of smooth surfaces.
Inconsistent Extrusion
Under-extrusion, blobs, and uneven flow from steam pressure fluctuations.
Brittleness / Snapping
Filament snaps when bent. This indicates hydrolysis damage — irreversible polymer chain degradation.
Storage Best Practices
Silica Gel Packets
Include 30–50g of indicating silica gel per spool. Blue/orange gel turns clear/green when saturated — regenerate in oven at 120°C for 2 hours. Replace or regenerate when color changes.
Vacuum Bags
Vacuum-seal spools with desiccant for long-term storage. Remove as much air as possible. Works especially well for Nylon, PC, and PVA that degrade quickly in ambient conditions.
Dry Box (Active)
For hygroscopic materials (Nylon, TPU, PVA), print directly from a dry box with PTFE tube feed. Options range from DIY cereal containers to purpose-built boxes like the EIBOS Cyclopes.
Sources (25+ manufacturer datasheets cross-referenced)
- Prusa Knowledge Base — Drying Filament (help.prusa3d.com)
- Bambu Lab Wiki — Filament Drying Recommendations (wiki.bambulab.com)
- 3DXTECH — Drying Instructions (3dxtech.com)
- Overture 3D — How to Dry 3D Printer Filament (overture3d.com)
- Sovol — Common Filament Drying Temperatures (sovol.eu)
- Polymaker Wiki — By Material Type (wiki.polymaker.com)
- Flashforge — Drying Temperature and Time (flashforge.com)
- eSUN — ePA-CF Technical Data Sheet (esun3d.com)
- Bambu Lab — PA6-CF, PLA-CF, PVA TDS (store.bambulab.com)
- BigRep — PA12 CF (bigrep.com)
- Essentium — PCTG Technical Data Sheet
- UltiMaker — How to Store PVA Material (ultimaker.com)
- Vision Miner — PEEK & PEI Print Guide (visionminer.com)
- 3DMaker Engineering — Drying Guide (3dmakerengineering.com)
- PrintDry — How to Dry Filaments (printdry.com)
- Fillamentum — Recommendation for Processing
- Snapmaker — TPU Drying Guide (snapmaker.com)
- Recreus — Moisture vs. Flexible Filaments (recreus.com)
Where sources disagree on specific values, we note the discrepancy and provide a conservative recommendation. See individual material notes for details.