Quick diagnosis
Oozing is a blob or drip that forms at a fixed point, such as a pause, a tool change, or the start of a travel move, where the nozzle sits idle over the print. That is a different guide from stringing, which is thin strands connecting two separate features after a travel move; if what you’re seeing is hair-like strands rather than blobs or drips, use the stringing guide instead of this one.
1. Manage heat creep during idle time
When the nozzle sits idle over hot filament for more than a few seconds, heat keeps softening material in the melt zone even though nothing is being extruded. That softened filament can expand and seep out on its own, especially if the hotend fan is undersized, clogged with dust, or not running at full speed during pauses. Check that the hotend cooling fan runs at full speed any time the nozzle is hot and idle, and keep pause or pre-print dwell times as short as the workflow allows.
2. Tune coasting and the nozzle wipe move
Coasting stops extrusion a short distance before a line ends, so the pressure still in the melt zone finishes the line instead of building up behind it. If coasting isn’t enabled, or the wipe move after the last extrusion is too short, that leftover pressure has nowhere to go and drips out as the nozzle travels to its next position. Enable a small coasting distance and a wipe move in your slicer, then increase both gradually if drips keep showing up at the same spot on every print.
3. Dial in pressure advance or linear advance
Pressure advance, or linear advance on Marlin firmware, tells the extruder to release pressure before a move ends instead of after, so flow actually stops when the nozzle needs it to. Without it tuned, pressure keeps pushing filament out for a moment after the printer thinks extrusion has stopped, and that shows up as ooze right where a travel move begins. Run your firmware’s calibration pattern or test print for pressure advance and apply the value it recommends instead of leaving the setting at zero.
4. Lower idle and standby temperatures
Multi-material setups and paused prints often leave an inactive nozzle sitting at or near full printing temperature, which keeps material soft enough to ooze onto the part or a wipe tower for as long as it waits. Set a standby temperature drop for idle tools or extruders, a meaningful step below the active printing temperature, so material inside the nozzle stiffens while it isn’t in use. Confirm the tool reheats before it resumes printing, so the drop doesn’t just trade ooze for a cold first line.
5. Shorten dwell before travel moves
Long pauses at the top of a retract, at a layer change, or before a slow travel move give softened filament more time to push out under gravity and leftover pressure. Trim unnecessary dwell out of your slicer’s start and travel sequences, avoid parking the nozzle over the part during a long retracted wait, and route travel moves over finished infill rather than open cavities. Each of these cuts down the chance that a drip lands somewhere visible on the finished print.
Nozzle oozing checklist
- Hotend fan runs at full speed whenever the nozzle is hot and idle.
- Coasting and a wipe move are enabled before travel.
- Pressure advance or linear advance is calibrated, not left at zero.
- Idle and standby temperatures drop meaningfully below printing temperature.
- Dwell time before travel moves is kept short.
- Travel routes avoid lingering directly over visible surfaces.
This is a different problem from stringing, which leaves hair-like strands between features rather than blobs or drips at a fixed point.