UltraDry Filament Storage

Proper filament storage is the difference between perfect prints and constant troubleshooting. PETG absorbs moisture quickly, and once it does, you’ll see stringing, popping, weak layers, and inconsistent extrusion.

This guide shows you exactly how to store filament the right way — short‑term, long‑term, and during printing — so your spools stay dry and print‑ready.

PETG is hygroscopic, meaning it absorbs moisture from the air. Even normal indoor humidity (40–60% RH) is enough to degrade print quality in hours, not days.

Moisture causes:

Popping and crackling during extrusion
Stringing and blobs
Cloudy or matte surfaces
Weak layer adhesion
Inconsistent flow

Proper storage prevents these issues before they start.

1. Keep humidity low

PETG stores best below 15% RH.

2. Keep air exchange minimal

Every time you open a container, moisture rushes in.

3. Keep desiccants fresh

Desiccants saturate over time and must be replaced or regenerated.

If you follow these three rules, your filament stays dry and print‑ready indefinitely.

If you’re actively printing with a spool, use:

Dry boxes

A sealed dry box with a filament feed port keeps humidity stable during printing.

Airtight containers

Simple gasket‑sealed bins work extremely well.

UltraDry™ Desiccant Packs

Drop one inside your container to maintain low humidity between prints.

Short‑term storage is all about preventing re‑absorption between sessions.

If you’re not using a spool for a while, you need a more controlled environment.

Vacuum bags

Remove air, add an UltraDry™ desiccant, and seal.
Perfect for long‑term storage and archiving.

Barrier‑layer bags

Thicker, multi‑layer bags slow moisture transfer dramatically.

Regenerated desiccants

Always use fresh or recharged desiccants for long‑term storage.

Label humidity levels

If you use humidity indicator cards, you’ll know when to swap desiccants.

Long‑term storage is about locking in dryness.

This is where most people make mistakes.

Freshly dried filament is extremely dry — but also extremely vulnerable.
It will re‑absorb moisture within minutes if left exposed.

Always store dried filament with UltraDry™ desiccants

Whether you use:

A filament dryer
An oven
A print‑while‑drying setup

…you should immediately transfer the spool into a sealed container with a desiccant while it’s still warm.

This locks in the dryness and prevents rapid re‑absorption.

Long prints (8–48 hours) expose filament to humidity the entire time.

To prevent moisture creep:

Use a dry box with a feed port

Keeps humidity stable throughout the print.

Add an UltraDry™ desiccant bottle inside the box

Maintains low RH for multi‑day jobs.

Avoid open‑air spooling

Even if your room “feels dry,” PETG will absorb moisture during long prints.

Traditional filament arrives partially wet — before you even open the bag.

UltraDry PETG solves this by:
Drying filament to <200 ppm moisture
Sealing it in barrier‑layer packaging
Including high‑capacity UltraDry™ desiccants
Maintaining a dry‑chain custody from factory → warehouse → you

This means your filament arrives ready to print, and stays dry longer with minimal effort.

Here’s the ideal setup for PETGUSA customers:

1. Active spool

Dry box
UltraDry™ desiccant bottle
Feed port to printer

2. Backup spools

Vacuum bags
UltraDry™ desiccant packs
Humidity indicator cards

3. Long‑term archive

Barrier‑layer bags
Regenerated desiccants
Airtight storage bin

This setup keeps every spool in perfect condition.

• DryFusion Technology
• Is Wet Filament Ruining Your Prints?
• UltraDry vs Traditional Filament
• PETG Troubleshooting Guide
• Best Temperatures for PETG
• UltraDry Filament Collection