PETG Troubleshooting Guide

PETG is one of the most reliable 3D printing materials — but when something goes wrong, it goes really wrong. Stringing, blobs, popping, poor adhesion, brittle parts… all of it is fixable once you understand the root causes.

This guide gives you the exact settings, fixes, and prevention steps to solve every major PETG issue.

PETG is strong, flexible, and temperature‑resistant — but it’s also:

More hygroscopic
More prone to stringing
More sensitive to cooling
Stickier at extrusion temperatures

Understanding these traits makes troubleshooting much easier.

Jump to the issue you’re dealing with:

Stringing / Oozing
Blobs / Zits on the Surface
Popping or Crackling Sounds
Poor Bed Adhesion
Under‑Extrusion
Layer Splitting
Brittle or Weak Parts
Nozzle Clogs
Overheating / Elephant’s Foot

Each section includes causes, fixes, and prevention.

Causes:

Wet filament
Retraction too low
Nozzle too hot
Travel moves too slow

Fixes:

Dry filament thoroughly
Increase retraction by 0.5–1.0 mm
Lower nozzle temp by 5–10°C
Increase travel speed to 150–200 mm/s

Prevention:

Store filament with UltraDry™ desiccants to stop moisture from creeping back in.

Causes:

Moisture in filament
Inconsistent extrusion
Retraction settings too aggressive

Fixes:

Dry filament
Enable “coast” or “wipe” in slicer
Reduce retraction distance

Prevention:

Use a dry box with desiccants during long prints.

Cause:

100% moisture.
This is the #1 sign your filament is wet.

Fixes:

Dry PETG at 65°C for 6–8 hours
Immediately store with UltraDry™ desiccants

Prevention:

Never leave PETG exposed to open air between prints.

Causes:

Bed too cold
Dirty build surface
Too much cooling
First layer too fast

Fixes:

Set bed to 75–85°C
Clean bed with IPA
Turn off part cooling for first 3–5 layers
Slow first layer to 20–30 mm/s

Prevention:

Use a consistent first‑layer routine.

Causes:

Partial clogs
Wet filament
Incorrect flow rate
Nozzle too cold

Fixes:

Increase nozzle temp by 5–10°C
Clean or replace nozzle
Set flow to 100–103%
Dry filament

Prevention:

Store filament properly and replace nozzles regularly.

Causes:

Nozzle too cold
Cooling too high
Moisture in filament

Fixes:

Increase nozzle temp
Reduce cooling to 0–30%
Dry filament

Prevention:

Use UltraDry™ PETG for consistent layer bonding.

Causes:

Wet filament
Too much cooling
Incorrect print temps

Fixes:

Dry filament
Reduce cooling
Increase nozzle temp

Prevention:

Store filament in airtight containers with desiccants.

Causes:

Contaminants
Burnt filament
Moisture expansion
Incorrect retraction settings

Fixes:

Cold pull
Replace nozzle
Lower temps slightly
Reduce retraction

Prevention:

Use high‑quality filament and keep it dry.

Causes:

Bed too hot
Nozzle too close
Insufficient cooling

Fixes:

Lower bed temp by 5°C
Re‑level Z offset
Increase cooling slightly

Prevention:

Dial in your first‑layer settings.

These are reliable starting points for most printers:

Nozzle: 235–250°C
Bed: 75–85°C
Cooling: 0–30%
Retraction: 0.8–1.2 mm (direct drive)
Speed: 40–60 mm/s
Flow: 100–103%

Fine‑tune from here based on your machine.

Most PETG problems trace back to moisture. UltraDry PETG solves this by:

Drying filament to <200 ppm moisture
Sealing it in barrier‑layer packaging
Including UltraDry™ desiccants
Maintaining a dry‑chain custody

This gives you consistent extrusion, stronger layers, and fewer tuning headaches.

• What Is UltraDry Filament?
• UltraDry vs Traditional Filament
• Is Wet Filament Ruining Your Prints?
• How to Store Filament Properly
• Best Temperatures for PETG

PETG is incredibly reliable once you understand how it behaves. With the right temperatures, proper storage, and moisture control, you can eliminate nearly every common issue and get consistent, high‑quality prints every time. UltraDry Filaments have been engineered to resolve this issue.