How to Store Filament to Prevent Moisture Damage

Moisture is the silent killer of 3D printing filament. Even a few hours of exposure to humid air can cause bubbling, stringing, weak layer adhesion, and failed prints. The good news: proper storage is simple and inexpensive. Here's everything you need to know to keep your filament dry and print-ready.

Why Moisture Ruins Filament

Most 3D printing filaments are hygroscopic — they actively absorb water molecules from the surrounding air. When wet filament is heated in your extruder, that moisture turns to steam, causing:

• Popping and crackling sounds during printing
• Bubbles and voids in your prints
• Excessive stringing and oozing
• Rough, matte surface finish instead of smooth and glossy
• Significantly weaker layer adhesion and part strength
• Inconsistent extrusion and under-extrusion

If you're experiencing any of these symptoms, wet filament is often the culprit — even if the spool looks fine from the outside.

Which Filaments Are Most Affected?

All filaments absorb moisture to some degree, but some are far more sensitive than others:

In Australia's humid coastal climates, even PLA can degrade noticeably within a week if left open on a shelf.

How to Store Filament Properly

Option 1: Resealable Bags with Desiccant (Minimum Standard)

The simplest approach: store each spool in a large resealable zip-lock bag with a silica gel desiccant packet. This is what most filament comes packaged in from the factory — including our eSUN PETG+ and eSUN PLA+ HS spools.

• Use bags large enough to fit the spool without forcing it
• Include 1–2 silica gel packets (50–100g) per spool
• Squeeze out as much air as possible before sealing
• Replace or recharge desiccant every few months

Option 2: Airtight Storage Containers (Recommended)

For a more robust solution, use airtight plastic storage containers (like Sistema or similar clip-lock boxes) sized to fit your spools. Add desiccant and a cheap hygrometer to monitor humidity inside the box. Aim to keep relative humidity below 15% inside the container.

• Stack multiple spools in one large container to save space
• Label containers by filament type for easy access
• Check the hygrometer periodically and recharge desiccant when it reads above 20%

Option 3: Dry Box / Filament Dryer (Best for Active Printing)

A filament dryer lets you print directly from a sealed, heated enclosure — keeping the filament dry even while it feeds into your printer. This is the gold standard for moisture-sensitive materials like PETG, Nylon, and TPU. Many makers use a food dehydrator as a cost-effective alternative.

How to Recharge Desiccant

Silica gel desiccant is reusable. When it's saturated (colour-indicating beads turn pink or the hygrometer reads high), simply spread it on a baking tray and bake at 120°C for 1–2 hours. Let it cool before returning to your storage containers.

How to Dry Wet Filament

If your filament has already absorbed moisture, you can rescue it by drying it before printing:

• Food dehydrator: 45–65°C for 4–8 hours (most popular method)
• Oven: Use the lowest setting (usually 50–60°C) with the door slightly ajar — be careful not to exceed the filament's glass transition temperature
• Dedicated filament dryer: Set to the recommended temperature for your material and dry for 4–6 hours

Recommended drying temperatures:

• PLA / PLA+: 45–50°C for 4–6 hours
• PETG / PETG+: 55–65°C for 4–6 hours
• ABS / ABS+: 60–70°C for 4–6 hours

Quick Storage Checklist

• ✅ Seal filament in airtight bags or containers immediately after use
• ✅ Always include desiccant — silica gel is cheap and reusable
• ✅ Use a hygrometer to monitor humidity (target: below 15% RH)
• ✅ Store in a cool, stable-temperature location away from direct sunlight
• ✅ Dry filament before printing if it's been exposed to air for more than a day or two (especially PETG and ABS)
• ✅ Don't leave spools on your printer overnight — return them to storage after each session

Taking care of your filament is one of the easiest ways to improve print quality and reduce failed prints. Browse our full range of 3D printing filaments — all shipped in sealed, desiccant-packed packaging to arrive in perfect condition. Questions? Get in touch with our team.