PETG Stringing Fix Guide

PETG strings more than PLA by nature — but you can get it under control. Here's every setting that matters, in order of impact.

⚡ Quick Fix Checklist

1.Dry the filament — wet PETG strings 10x worse. 65°C for 4–6 hours.

2.Increase retraction to 4–6mm (Bowden) or 1–2mm (direct)

3.Lower temp to 230°C — go down 5°C at a time

4.Increase travel speed to 150–200 mm/s

5.Enable Z-hop at 0.2mm to lift over strings

Why PETG Strings More Than PLA

PETG has higher viscosity and surface tension than PLA at print temperatures. When the nozzle moves between parts, PETG "stretches" instead of breaking cleanly. It also absorbs moisture aggressively — wet PETG strings dramatically worse because steam pressure inside the melt prevents clean retraction.

The good news: PETG stringing is fixable. It just requires more precise retraction tuning than PLA.

Fix 1: Dry Your PETG First

Do this before adjusting any settings.

Wet PETG can string even with perfect retraction. If you hear crackling or see steam, nothing else will fully fix it. Dry at 65°C for 4–6 hours then test again.

Fix 2: Retraction Settings

PETG needs more retraction than PLA, but over-retraction causes gaps and grinding. The window is narrow — tune carefully.

Setting	Direct Drive	Bowden	Start Point
Retraction Distance	1.0–2.0 mm	4.0–6.0 mm	Start low, +0.5mm each test
Retraction Speed	30–45 mm/s	40–60 mm/s	Faster than PLA
Extra Restart Distance	0 to −0.2 mm	0 to −0.3 mm	Negative prevents blobs
Wipe Before Retract	1.5–2.5 mm		More than PLA

Over-retraction warning: Too much retraction with PETG causes gaps at seam lines and can grind the filament. If you see holes appearing, reduce retraction by 0.5mm.

Fix 3: Temperature vs Stringing

Temperature	Stringing	Notes
250°C+	Severe	Too runny — always strings
240°C	Moderate-High	Many brands too hot here
225–235°C ⭐	Low–Moderate	Sweet spot for most PETG
220°C	Very Low	Risk under-extrusion below 220°C

Fix 4: Slicer Anti-Stringing Settings

Combing / Avoid Crossing Perimeters

Very High

Routes travels inside the model. Reduces visible strings dramatically since they're hidden inside.

Z-Hop (0.2mm)

High

Lifts nozzle before travel so it doesn't drag strings over printed surfaces. Essential for PETG.

High Travel Speed (150–200 mm/s)

High

Less hang time = less material oozing. PETG is thick enough that speed genuinely helps.

Linear Advance / Pressure Advance

Medium

Compensates for PETG's high pressure in the hotend. Reduces ooze on direction changes.

PETG vs PLA: Stringing Difficulty

Factor	PLA	PETG
Natural stringing tendency	Low	High
Effect of moisture on stringing	Moderate	Severe
Retraction window	Wide	Narrow
Can be fully eliminated?	Yes	Mostly (some always remains)

Expectation management: Even perfectly tuned PETG may have very fine, wispy threads in complex models. This is normal. The goal is to reduce stringing, not necessarily eliminate every strand.