3D printing with PLA filament is one of the easiest and most rewarding experiences for beginners and professionals alike. However, nothing ruins a print quite like brittle filament. If you’ve ever gone to print a model only to have your PLA snap, crack, or tangle midway, you’ve likely encountered the results of poor filament storage. The good news? Preventing brittleness is as simple as proper storage. In this article, we’ll break down the causes of brittle PLA filament, explain how to store it correctly, and help you get the best performance from every spool you buy.
What Makes PLA Filament Brittle?
Polylactic Acid (PLA) is a plant-based thermoplastic known for its ease of use, eco-friendliness, and relatively low printing temperature. However, it comes with one major weakness — it’s hygroscopic. That means it absorbs moisture from the air. Once PLA takes in water molecules, the filament structure begins to degrade, becoming brittle, prone to breakage, and harder to print. Besides moisture, other factors like UV light, oxygen, and fluctuating temperatures can gradually reduce the quality of PLA. Even if your filament isn’t exposed to visible water, sitting out in an open room can degrade it faster than you expect.
How to Tell If Your PLA Has Gone Brittle
Brittle PLA doesn’t just show itself during printing — you’ll often feel or hear the damage as soon as you handle the spool. Common signs include:
- Snapping or cracking while unspooling
- Stiffness or fragility when bending the filament
- Uneven extrusion during printing
- Dusty or chalky residue on your hands after handling
If you notice any of these symptoms, it’s time to evaluate how you’re storing your filament and whether it can be revived with drying.
The Ideal Environment for PLA Filament
To avoid brittleness, PLA should be stored in a stable, dry environment. Here’s what ideal storage conditions look like:
- Humidity: Keep it below 20–30% relative humidity
- Temperature: Store at room temperature (18°C to 22°C is ideal)
- Light: Avoid exposure to direct sunlight or UV lamps
- Air: Limit oxygen exposure using airtight storage
Even in areas where the air feels “dry,” ambient moisture can creep in slowly over days or weeks. That’s why proper containment is key.
Best Storage Methods to Keep PLA Dry
You don’t need to build a high-tech chamber to store PLA properly. A few simple and affordable solutions can make a big difference:
Vacuum-Sealed Bags
These bags are designed to remove air and moisture, locking in freshness. Use silica gel packs inside to help maintain dryness.
Airtight Plastic Containers
A simple latching food-grade container can work wonders. Add a hygrometer to monitor humidity and throw in desiccant packs for extra protection.
Filament Dry Boxes
These purpose-built boxes are made for storing spools while actively keeping them dry. Some even include filament feed holes for direct printing.
DIY Dry Box Setup
Repurpose a plastic bin with a rubber gasket lid, add a few holes and fittings for filament feeding, and you have a low-budget, high-performance solution.
Essential Accessories to Help Store PLA
To take your filament storage even further, consider these helpful accessories:
- Silica Gel Desiccants: Rechargeable ones last longer and can be dried in the oven
- Humidity Indicator Cards: Easy visual check of humidity levels inside storage
- Digital Hygrometers: Track real-time RH inside your containers
- Rechargeable Dehumidifiers: Keep containers dry without needing electricity
You can find many of these tools and accessories right here on filalab.shop — carefully curated for filament care and 3D printing excellence.
How Long Does PLA Last in Storage?
With proper storage, PLA filament can easily last 12 to 24 months without quality loss. However, improperly stored PLA can go brittle in as little as 2–3 weeks, especially in humid climates. If you catch your filament early, a few hours in a dedicated filament dryer (or an oven at 40–45°C) can sometimes restore it to usable condition.
What About Traveling or Storing Multiple Spools?
If you store more than one type of filament or frequently travel with your printer setup, organization matters. Here are a few bonus tips:
- Label Each Spool: Mark the date of opening and filament type
- Use FIFO (First In, First Out): Rotate older spools forward so you use them before newer ones
- Store Vertically: Reduces bending stress and helps preserve shape
Final Tips to Prevent PLA Brittleness
- Always reseal after printing, even for short pauses
- Store spools vertically or on a dry rack
- Never leave filament on your printer overnight, especially in humid rooms
- Avoid touching filament with bare, oily hands — oils can attract moisture and dust
Conclusion
PLA filament is one of the most accessible materials in 3D printing, but it’s also one of the most sensitive to poor storage habits. By understanding how moisture and air affect your filament, and investing in proper storage tools like vacuum bags or filament dry boxes, you can ensure longer shelf life and more reliable printing sessions. Want to upgrade your filament storage setup? Check out the latest PLA filaments, dry boxes, desiccants, and storage solutions at filalab.shop — your trusted resource for smarter, cleaner 3D printing.