Retraction in 3D printing – what it is and how to set it

Retraction means the extruder pulls the filament back just before the toolhead travels over empty space. It lowers the pressure in the nozzle so plastic does not ooze during the travel move. Badly set retraction is the most common cause of "spider webs" (stringing) between parts of a print.

Filament manufacturer's guidance comes first. Every manufacturer has its own formulations and publishes its own parameters – nozzle, bed and chamber temperature, drying, cooling. Even the same material (e.g. PETG) from two brands may need different settings. Treat the values in this guide as a starting point: check the technical data sheet (TDS) and the spool label first, and if something is missing, ask the filament manufacturer for guidance.

Main retraction parameters

• Length – how many millimetres the filament is pulled back.
• Speed – how fast the extruder retracts and primes.
• Z-hop – lifting the nozzle during travel so it does not catch the print.
• Wipe / coasting – wiping the nozzle or stopping extrusion slightly before the end of a path.

Starting values

• Direct drive (extruder on the toolhead): length usually 0.4–1.5 mm, speed approx. 30–45 mm/s.
• Bowden (extruder on the frame, filament in a tube): length usually 3–6 mm, speed approx. 35–50 mm/s.

These are starting points – the exact value is found with a test, as it depends on the hotend, filament and temperature.

Tuning retraction step by step

1. Set the right temperature first (too hot increases oozing – see the temperature chart) and pressure advance.
2. Print a retraction test (in Orca Slicer: Calibration → Retraction test), which changes the length every few layers.
3. Pick the shortest length at which strings disappear.
4. Change the speed only if length alone is not enough.

Common mistakes

• Too much retraction – filament softens in the transition zone and can clog the hotend (see heat creep); gaps also appear at the start of paths.
• Wet filament – no retraction will remove strings from wet PETG or nylon. Dry the filament first.
• Worn or leaking nozzle – oozing despite good settings often means a mechanical problem.

Retraction and material

PLA usually prints cleanly with short retraction. PETG is stringier – a lower temperature and dry filament help. TPU needs very little retraction or none at all, because flexible filament jams easily.

On Revon printers, the Revotech profiles for Orca Slicer already include retraction settings tuned for the main materials.