When it comes to 3D printing, nothing is more frustrating than pouring hours into a model only to get poor layer adhesion, stringy finishes, or mysterious bubbles in your prints. The hidden culprit? Moisture in your filament. It’s one of the most overlooked problems by beginners and even seasoned printers — and drying your filament might be the simplest fix for all of it.
Let’s dive into why drying filament is essential, how to do it correctly, and how to store it afterward to avoid setbacks on your next big print.
Why Does Filament Absorb Moisture?
Many 3D printer filaments are hygroscopic — meaning they absorb moisture from the air. While this might not seem like a big deal, even small amounts of water inside the filament can turn into steam when it hits the hot end of your printer. This causes air pockets, popping noises, bubbling, and inconsistent extrusion.
Some filaments, like Nylon, PETG, and PVA, are particularly moisture-sensitive. Even PLA, which is more forgiving, can still suffer from humidity exposure — especially in climates with high ambient moisture. That’s why, whether you’re printing functional parts or aesthetic models, keeping your filament dry is non-negotiable.
Signs That Your Filament Needs Drying
If you’ve been troubleshooting weird print behavior with no success, your filament might be the issue. Here’s what to look for:
- Popping or sizzling sounds during extrusion.
- Stringy prints or excessive oozing between travel moves.
- Poor layer adhesion or fragile printed parts.
- Bubbles or inconsistent surfaces.
These symptoms are especially common after filament has been left out for more than a few days — even in a closed spool box if not airtight.
How to Dry Filament (The Right Way)
There are several methods to dry filament, but not all are equally safe or effective. Here’s what works best:
1. Use a Filament Dryer
Filament dryers are purpose-built devices that maintain a controlled temperature over time, drying your filament safely without damaging it. Many can even hold the spool while you print, keeping it dry mid-use.
2. Use a Regular Oven (With Caution)
If you don’t have a dryer, a kitchen oven can work — but it comes with risks. You’ll need an oven that holds low temperatures consistently, and it’s essential to monitor it closely.
Here’s a general guide:
- PLA: 40–45°C for 4–6 hours
- PETG: 55°C for 6 hours
- Nylon: 70–80°C for 8–12 hours
Always use an oven thermometer — most kitchen ovens fluctuate more than you think!
3. Use a Food Dehydrator
These are a great alternative and more consistent than ovens. With a few modifications (like larger trays), they can hold filament spools well and operate at safe drying temps for long periods.
How Long Should You Dry Filament?
Drying time varies based on the material and how saturated the filament is. Here’s a cheat sheet:
- PLA: 4–6 hours at 40–45°C
- PETG: 6 hours at 55°C
- Nylon: 8–12 hours at 70–80°C
- TPU: 4–6 hours at 40°C
Overdrying isn’t typically an issue unless the temperature is too high — so longer is better than hotter.
Store Your Filament the Right Way After Drying
Drying your filament is only half the battle. The moment you pull a spool out of a dryer, it begins absorbing moisture again. That’s why proper storage is just as important.
Use Airtight Containers with Desiccants
Plastic bins with rubber seals are ideal. Add a few silica gel packs to trap humidity.
Try Vacuum-Sealed Bags
If you have limited space, vacuum bags are an affordable way to keep humidity out — especially if you rotate through filaments often.
What Happens If You Don’t Dry Filament?
Ignoring filament moisture doesn’t just lead to aesthetic problems — it can damage your printer over time. Moisture causes steam pockets, which lead to nozzle clogs, heat creep, and extruder skipping. Worse, fragile prints are more likely to fail under stress, leading to lost time and wasted material.
So if you’ve ever felt like your printer is betraying you — it might not be the printer at all. It might just be wet filament.
Best Beginner Filaments That Handle Moisture Well
If you’re just getting started and want a bit more forgiveness, go with:
- PLA and PLA+ – Low sensitivity to moisture, prints well even with slight exposure.
- PETG – Great for functional parts, but benefits a lot from drying.
Final Thoughts
Whether you’re a hobbyist or a pro, drying your filament is an easy win for better print quality, longer-lasting spools, and fewer printer issues. By investing a little time in drying and storing your filament properly, you’re not just improving your prints — you’re protecting your machine and your time.