Start with roughly what your machine uses for PLA, then shorten the distance and reduce the speed. On a direct-drive machine that means well under a millimetre; on a Bowden machine, a few millimetres.
But the order matters more than the numbers, and retraction is the third thing to fix, not the first.
Fix these before touching retraction
- Dryness. Wet PETG strings no matter what the retraction is set to. A cycle at 65 °C, held for 4 to 6 hours, has to come before any tuning at all.
- Nozzle temperature. PETG's stringing rises steeply with heat. Come down from 250 °C in small steps until the strings stop, then go one step back up.
People who skip those two spend days on retraction and never solve it, because the retraction was never the problem.
Why PETG wants less retraction than PLA
PETG stays soft and stretchy over a wider temperature range. A long, fast retraction pulls that soft filament back up into the cold zone of the hotend, where it grips, and the next extrusion has to push it back through a constriction it now fits badly.
The results are the two classic PETG faults: under-extrusion after travel moves, and a grinding extruder. Both look like a retraction that is too small, which is the trap — the instinct is to increase it, and increasing it makes both worse.
Settings that help more than distance
- Retraction speed down. Slower withdrawal deforms the soft filament less than a shorter distance does.
- Travel speed up. Less time in the air per travel means less thread pulled.
- Z-hop off, or minimal. It lengthens travel time and adds oozing opportunity.
- Coasting and wipe. Both reduce pressure at the end of an extrusion, which is where a string starts.
Test it properly
Print a retraction tower — two thin pillars with a gap, sliced with a script or plugin that steps the retraction distance every few millimetres of height. It takes minutes and it answers the question for your machine, your hotend and your spool together.
That result beats any published figure, including everything above.
Temperature and retraction are tuned together, so work through PETG print temperature alongside this — and check the drying schedule on the PETG page before either.