The definitive retraction reference. Every material, every extruder type — with exact starting values and how to tune from there.
When the nozzle moves between parts without extruding ("travel move"), molten filament oozes out — creating strings. Retraction pulls filament backward to relieve nozzle pressure, preventing ooze. Too little = stringing. Too much = gaps, grinding, clogs.
| Material | Direct Drive Distance | Direct Drive Speed | Bowden Distance | Bowden Speed |
|---|---|---|---|---|
| PLA | 0.5–2.0 mm | 25–45 mm/s | 3.0–6.0 mm | 40–60 mm/s |
| PLA+ | 0.5–2.0 mm | 25–45 mm/s | 3.0–6.0 mm | 40–60 mm/s |
| PETG | 1.0–2.0 mm | 30–45 mm/s | 4.0–6.5 mm | 45–60 mm/s |
| ABS | 1.0–2.0 mm | 30–45 mm/s | 4.0–6.0 mm | 40–55 mm/s |
| ASA | 1.0–2.0 mm | 30–45 mm/s | 4.0–6.0 mm | 40–55 mm/s |
| TPU 95A | 0.5–1.5 mm | 15–25 mm/s | 0–2.0 mm | 15–20 mm/s |
| Nylon PA12 | 1.0–2.0 mm | 25–40 mm/s | 4.0–6.0 mm | 40–55 mm/s |
| Carbon Fiber | 0.5–1.5 mm | 20–35 mm/s | 3.0–5.0 mm | 35–50 mm/s |
| Aspect | Direct Drive | Bowden |
|---|---|---|
| Retraction distance needed | Short (0.5–2mm) | Long (3–7mm) |
| Why different? | Extruder is close to nozzle, short path | Long PTFE tube compresses, more retract needed |
| Flexible filament (TPU) | Works well | Very difficult |
| Speed capability | Higher (lighter printhead) | Lower |
Print a retraction test tower
Download a retraction tower model (Thingiverse/Printables). It prints multiple columns at different retraction values. Visually identify where stringing stops.
Start with the table values above
Use the starting point for your material and extruder type. Don't guess — start from known-good values.
Adjust distance first
Change distance in 0.5mm steps. Find the minimum that eliminates stringing — over-retraction causes more problems than under.
Then tune speed
Once distance is set, try increasing speed by 5 mm/s increments. Faster is generally better up to the extruder's limit.
Tune extra restart distance
If you see holes at seam lines after retraction, set extra restart distance to 0 or slightly negative (−0.1mm) to compensate.
❌ Over-retraction
Symptoms: Gaps at seam lines, grinding sounds, clogs
Fix: Reduce distance by 0.5mm at a time
❌ Retraction too slow
Symptoms: Strings despite correct distance
Fix: Increase retraction speed to 40+ mm/s
❌ Ignoring wet filament
Symptoms: Strings despite perfect settings
Fix: Dry filament before tuning
❌ High retraction on TPU
Symptoms: Jams, buckled filament in extruder
Fix: Max 1.5mm for flexible materials
PLA direct: 0.5–2.0mm / 35mm/s
PLA Bowden: 3–6mm / 45mm/s
PETG direct: 1–2mm / 40mm/s
PETG Bowden: 4–6.5mm / 50mm/s
TPU direct: 0.5–1.5mm / 20mm/s
TPU Bowden: 0–2mm only