Materials
How to Dry 3D Printer Filament
How to dry filament by material, with a sourced temperature-and-time table for seven plastics, the three methods that work, and the one that does not.
Short answer
To dry 3D printer filament, heat the spool gently and steadily, below the plastic’s softening point, for hours rather than minutes, in a filament dryer or a forced-air oven you have checked with a thermometer. Published manufacturer settings put PLA at 45–55 °C for 6–8 hours and PETG at 55–65 °C for 6–8 hours. When your spool’s data sheet gives a different number, follow the data sheet.
Knowing how to dry filament fixes print problems that look like bad settings. Filament absorbs moisture from the air, and that water turns to steam in the hot nozzle. The result is popping or hissing, heavy stringing, rough walls, small bubbles, and weaker layers.
The numbers here are published manufacturer ranges, not results from our own drying tests. They were compiled on November 10, 2026 from Bambu Lab’s drying wiki, the Prusa Knowledge Base, and Bambu Lab and Polymaker data sheets.
Check whether your filament is actually wet
Your filament is probably wet if the nozzle pops or hisses, strings ignore retraction changes, or walls come out rough and bubbly. Polymaker’s wet-filament guide adds weak, brittle layers and uneven extrusion.
Those symptoms overlap with temperature and retraction problems, so treat them as a reason to dry first, not as proof. The cleanest test is to print the same small part from a freshly opened sealed spool and from the suspect spool at identical settings. If only the old spool strings and pops, it is wet, not mistuned.
A hygrometer in your storage box warns you about damp air before symptoms start.
Look up the drying temperature and time for your material
Most common filaments dry at 45–90 °C for 4–12 hours, depending on the plastic. The table collects published figures from Bambu Lab and Prusa, with Polymaker as a third PLA check.
| Material | Drying temp (°C) | Time (h) | Notes |
|---|---|---|---|
| PLA | 45–55 | 6–8 | Bambu PLA Basic 50 °C, 8 h. Prusament 45 °C, 6 h. Polymaker PolyLite 55 °C, 6 h. |
| PETG | 55–65 | 6–8 | Bambu 60–65 °C, 8 h. Prusament 55 °C, 6 h. See PETG print settings. |
| TPU | 60–70 | 4–8 | Bambu 70 °C, 8 h, drying required. Prusament 60 °C, 4–6 h. |
| ABS | 75–85 | 8 | Bambu 75–85 °C, 8 h. |
| ASA | 75–85 | 4–8 | Bambu 75–85 °C, 8 h. Prusament 80 °C, 4 h. |
| Nylon (PA) | 75–90 | 6–12 | Bambu fiber-filled PA 75–85 °C, 8–12 h. Prusament PA11 CF 90 °C, 6 h. |
| PC | 75–85 | 5–8 | Bambu 75–85 °C, 8 h. Prusament PC Blend 85 °C, 5 h. |
Check the spool too. Bambu’s PLA Basic data sheet rates its spool to 70 °C, and Prusa says its older black spools loosen above 45 °C.
Dry filament in a filament dryer
To dry filament in a filament dryer, set it to your material’s temperature and run the full time. It is the simplest method because it holds that temperature around the spool. Prusa’s advice is to check that the dryer’s maximum reaches your material’s drying temperature.
- Look up the material in the table and set the dryer to that temperature and time.
- Use a rotating mode if the dryer has one. Bambu says static drying does not suit PLA, PVA, or TPU, because their layers can stick or deform.
- Run the full time, then print from the dryer or move the spool straight into sealed storage.
The display shows the dryer’s set point, not a reading at the spool, so a thermometer beside the filament is a cheap check.
Dry filament in an oven
To dry filament in an oven, use a forced-air oven at the table temperature and confirm it with an oven thermometer. Prusa warns that home oven swings can damage PLA, and that many ovens cannot be set low enough.
- Preheat to the table temperature and read the oven thermometer, not the dial.
- Place the spool away from the heating elements, where it cannot tip.
- Dry for the listed time, then let the spool cool.
Bambu recommends a forced-air convection oven at least 250 mm deep, 250 mm wide, and 90 mm high for one of its 200 mm × 67 mm spools. Bambu advises against kitchen ovens, because spots near the elements get hot enough to damage the spool or filament. It also warns that some third-party spools are not heat-resistant enough and can deform.
Dry filament on a printer heatbed
You can dry filament on a printer heatbed only on enclosed printers whose maker documents it, with the spool covered on the bed. Bambu’s wiki says the open-frame A1, A1 mini, A2L, and P1P cannot be used for this, so if you are working through our Bambu Lab A1 setup guide, use a dryer or oven instead.
On supported models, Bambu’s steps are to unload the toolhead, lower the bed, cover the spool with a heat-resistant lid or the filament box, and flip it halfway through. Bed settings run hotter and longer than oven settings: 60–70 °C for 12 hours for PLA Basic and 75–85 °C for 12 hours for PETG.
Dry filament without a dryer or oven
Without a dryer or oven, use a food dehydrator that reaches your material’s temperature, or an enclosed printer’s heatbed. Prusa notes that dehydrators usually run low, so check the maximum against the table.
A sealed bin with desiccant is not a drying method. UltiMaker states that storing filament with silica desiccant does not dry it, because drying needs heat.
Do not use a microwave. Bambu rules it out because microwave heating is uneven and the temperature cannot be controlled.
Keep filament dry after drying
Move dried filament straight into a sealed bin or bag with active desiccant, and aim for under 20% relative humidity, the figure on Bambu’s data sheets. Bambu’s wiki says freshly dried filament in a 55% RH room can absorb enough moisture to affect prints within 2–12 hours.
A hygrometer inside the box shows whether the desiccant still works. Bambu says to regenerate saturated silica gel at 80–90 °C for 1–3 hours, never above 100 °C. For long prints in moisture-sensitive plastics, Polymaker suggests feeding straight from a dryer or dry box.
Caution
Never dry PLA near its glass transition temperature. Bambu’s PLA Basic data sheet lists 60 °C, and Polymaker’s PolyLite PLA data sheet lists 61 °C. Prusa warns that going above its drying temperatures makes filament soften and stick together on the spool. Stay at 45–55 °C for PLA.
Before you blame your settings
Run through this checklist before you change temperature, retraction, or speed.
- Spool dried at the table temperature for the full time, or freshly opened from a sealed bag
- Oven or dryer temperature confirmed with a thermometer
- Spool stored sealed with active desiccant since drying
- Storage hygrometer reading under 20% RH
- Same test part reprinted at the same settings after drying
- Stringing compared against a fresh spool of the same material
Questions
Does PLA need to be dried?
Usually not, unless it shows wet symptoms or has been stored open. Prusa says PLA changes little when it takes up moisture, and Polymaker rates it low-sensitivity and says to dry it only when it has absorbed moisture. If an older PLA spool pops, strings, or prints rough walls, dry it at 45–55 °C for 6–8 hours.
How long does it take to dry filament?
Most filament takes 4–12 hours, depending on the material and method. Bambu’s forced-air oven settings run 8 hours for PLA, PETG, TPU, ABS, ASA, and PC. Prusa lists 4–6 hours for many Prusament materials. Heatbed drying takes longer, about 12 hours in Bambu’s table. Higher heat is not a shortcut, because Prusa warns it damages filament even over a shorter time.
Can you microwave filament to dry it?
No. Bambu Lab’s drying wiki says not to use a microwave, because microwave heating is uneven and the temperature cannot be controlled. Filament needs a steady temperature below its softening point for several hours, which a microwave cannot hold. Use a filament dryer, a forced-air oven checked with a thermometer, or a food dehydrator that reaches your material’s temperature.
How do you dry filament without a dryer?
Use a forced-air oven or a food dehydrator that reaches your material’s drying temperature, and check it with a thermometer. Enclosed Bambu printers can also dry spools on the heatbed, but Bambu says the open-frame A1 cannot. A sealed bin with desiccant keeps filament dry after drying, but it will not rescue a spool that is already wet.
Does drying filament make it brittle?
It can, if you overheat it or dry it too often. Prusa asks you to keep to its listed times to prevent overdrying. Bambu notes that repeated heat-and-cool drying cycles can make PC filament brittle and more likely to snap while feeding. Dry once at the table temperature, then keep the spool sealed with desiccant so it does not need drying again soon.
Fixed it?
If prints come out clean, keep that spool sealed so it stays dry. Still stringing on dry PETG? Go to the nozzle temperature and retraction steps in our PETG print settings guide.
Keep going
Browse the Guides hub for more setup and settings walkthroughs.