Filament Storage & Drying

Most filaments are hygroscopic — they absorb water from the air. When wet filament hits the hot nozzle, that moisture flashes to steam, disrupting the flow. The result is stringing, popping or crackling sounds, rough surfaces, weak layer bonding, and brittle parts.

Nylon, TPU, PVA, PETG, and all CF/GF composites drink moisture fastest — sometimes unusable within a day of open exposure. PLA and ABS are slower but not immune.

Suspect moisture when a spool that printed fine before starts misbehaving for no other reason:

• Hissing, popping, or steam at the nozzle
• Fuzzy, stringy surfaces that weren't there before
• Visible bubbles or rough texture in extruded lines
• Parts that snap easily along layer lines

If a known-good profile suddenly produces bad prints, dry the filament before changing settings.

Keep spools sealed and dry:

• Store in airtight bins or vacuum bags with desiccant (silica gel) inside
• Keep a hygrometer in the container — aim for under 20% relative humidity
• Recharge desiccant when it's saturated (bake or use the indicating-bead color)
• For thirsty materials, feed directly from a sealed dry box while printing

To rescue wet filament, hold it above its glass-transition temperature long enough to drive water out:

• PLA: 45–50°C for 4–6 hours
• PETG: 60–65°C for 4–6 hours
• ABS/ASA: 70–80°C for 4–6 hours
• Nylon / CF blends: 70–80°C for 8–12 hours

Use a dedicated filament dryer or a food dehydrator. A kitchen oven works but is risky — many run hotter than their dial and can deform or melt a spool.