Successful 3D printing begins long before the first layer is laid down. Improper storage of resin and filament can lead to poor quality prints, failed jobs, and even permanent damage to your equipment. Inconsistent extrusion, stringing, brittle prints, layer delamination, or incomplete curing are often traced back to materials that were not stored correctly. This comprehensive guide will show you how to properly store both resin and filament to maximize their lifespan and performance.
Why Proper Storage Matters for 3D Printing Materials
Both resin and filament are highly sensitive to environmental conditions, especially moisture and temperature. Even short-term exposure to the wrong environment can cause irreversible changes in their chemical structure or mechanical properties.
Moisture absorption is the most common problem. Filaments like PLA, ABS, PETG, and nylon are hygroscopic, meaning they absorb water from the air. When wet filament is printed, the water inside the material vaporizes, causing bubbling, rough surfaces, weak layer adhesion, and poor mechanical strength.
Resin, although less porous than filament, also degrades when exposed to light, air, and temperature fluctuations. Unsealed resin can polymerize prematurely or lose its curing consistency, resulting in incomplete prints, tacky surfaces, or brittleness.
Proper storage keeps your materials fresh, reliable, and ready to produce high-quality prints consistently.
How to Store 3D Printing Filament Correctly
1. Keep Filament Dry
Use Airtight Containers:
Store filament spools in airtight plastic containers or resealable bags immediately after use. Add desiccant packs inside to maintain a dry environment.
Dry Boxes for Active Use:
If you frequently print, consider using filament dry boxes that can hold spools while feeding filament into the printer. Some dry boxes even include built-in heaters and hygrometers.
Monitor Humidity Levels:
Aim to keep the relative humidity below 20% inside your storage containers. A simple humidity indicator card can help you verify if desiccants need replacement.
Filament exposed to high humidity for even a few hours can start showing signs of degradation during printing.
2. Avoid Sunlight and UV Exposure
Filament exposed to sunlight or strong UV sources can become brittle and discolored. Store filament in opaque or dark containers and keep them away from windows or UV lighting.
3. Control Storage Temperature
High temperatures can warp or soften filaments like PLA, causing them to deform even on the spool. Store filament in a cool, stable-temperature room, ideally between 15–25°C. Avoid storing filament near heaters, vents, or in garages that experience extreme seasonal temperature changes.
4. Label and Organize Filament
Always label spools with the material type, color, and purchase date if it is not already printed on the spool. Proper labeling helps track the age of materials and use older spools first before they degrade.
Organize filaments by material family (PLA, ABS, PETG, etc.) to avoid confusion and cross-contamination.
5. Rejuvenate Wet Filament
If filament becomes wet, it can often be saved by drying it. Filament dryers, food dehydrators, or controlled oven drying at low temperatures (around 45–55°C) for several hours can restore filament to a printable condition.
Nylon and PVA are particularly sensitive to moisture and may need drying even when new if exposed during shipping.
How to Store Resin Properly
1. Keep Resin in a Dark, Cool Place
Use Original Containers:
Always store unused resin in its original, opaque bottle. These bottles are designed to block UV light and minimize air contact.
Seal Tightly After Use:
After pouring resin into your vat, immediately reseal the bottle tightly. Leaving resin exposed to air will cause oxidation and chemical degradation over time.
Store Away from Sunlight:
Even a few minutes of direct sunlight exposure can start polymerizing resin inside the bottle. Store resin in dark cabinets, drawers, or specially designed resin storage boxes.
2. Maintain a Stable Temperature
Resin performs best when stored at a stable temperature between 18–25°C. Exposure to heat can thicken or partially cure the resin, while cold can cause it to separate or crystallize.
Avoid storing resin in areas prone to temperature swings, such as basements, attics, or unheated garages.
3. Shake Before Each Use
Resin components can separate over time. Always shake the bottle gently but thoroughly before pouring resin into the vat. This ensures even mixing of pigments and reactive components for consistent curing and color quality.
Failing to shake resin can lead to uneven prints with strange mechanical properties or inconsistent coloring.
4. Filter and Reuse Resin Properly
After printing, you may want to reuse leftover resin in the vat. Always filter it through a fine mesh or paper filter before returning it to the bottle. Filtering removes cured resin particles that can ruin future prints or damage your FEP film.
Never mix different brands or types of resin unless specifically allowed by the manufacturer.
5. Limit Resin’s Time in the Vat
Resin sitting uncovered in the printer vat can absorb moisture from the air or degrade from ambient light. If you will not print for more than a day, it is better to pour the resin back into its bottle after filtering.
Extended exposure in the vat increases the risk of partial curing, thickening, or separation.
Advanced Storage Tips
Use Vacuum Sealing for Filament:
For long-term filament storage, vacuum-sealing with fresh desiccant packs is one of the most effective methods. Vacuum-sealed filament stays dry and clean for months or even years.
Invest in a Filament Storage Cabinet:
High-end storage cabinets equipped with desiccant regeneration systems and digital humidity controls provide the ultimate filament preservation environment.
Resin Refrigerator:
In very hot climates, some users store resins in specialized small refrigerators that maintain a cool but not freezing temperature. Normal food refrigerators are not recommended because of humidity fluctuations.
Common FAQs About Storing Resin and Filament
How long does filament last if stored properly?
Most filament types can last 12–24 months or longer if stored in dry, cool, dark environments. Nylon and PVA are more sensitive and may require re-drying periodically.
Can old resin still be used?
If stored correctly, resin can last 12–18 months. Always inspect resin for signs of thickening, unusual odors, or clumping before using old bottles.
What happens if filament absorbs moisture?
Moist filament leads to poor extrusion, visible print defects like bubbling and stringing, and reduced mechanical strength. Drying can often restore usability.
Should I store filament in the printer?
Leaving filament mounted on the printer exposes it to ambient humidity and dust. It is better to remove it and store it in a sealed container between prints, especially in humid environments.
How do I know if resin has gone bad?
Signs of degraded resin include uneven coloration, clumping, thickened texture, poor curing during printing, and unusual smells. Discard resin that shows these signs.
Conclusion
Proper storage of resin and filament is critical to maintaining consistent, high-quality 3D prints. Moisture, temperature, and light are the biggest enemies of your materials. By using airtight containers, desiccants, dry boxes, and dark storage spaces, you can protect your investments and avoid common failures like splitting, bubbling, or poor curing. A little effort in material care goes a long way toward maximizing print success, extending the life of your supplies, and ensuring frustration-free printing sessions every time.