Quick answer
PLA stringing is the thin, hairy wisps of plastic left between separate parts of a print, and it comes mostly from too high a nozzle temperature, too little retraction, and damp filament. Lower the nozzle in 5C steps (try 200-210C), make sure retraction is set correctly for your extruder type, and dry the spool if it has been open for a while. A quick retraction/temperature test print will confirm the fix in under an hour.
Why PLA strings
Stringing (also called “oozing” or “cobwebbing”) happens because molten PLA keeps flowing out of the nozzle while the print head travels across open space. When the pressure inside the hot end is not relieved during those travel moves, a little plastic leaks out and gets dragged across the gap, leaving a fine string. The three biggest contributors are heat (hotter plastic is runnier and oozes more), retraction (pulling filament back relieves nozzle pressure), and moisture (water in the filament flashes to steam and pushes plastic out continuously). Dialing in temperature and retraction fixes the large majority of PLA stringing.
1. Lower the nozzle temperature
PLA prints well across a fairly wide band, so start at the cooler end. If you are stringing at 215-220C, drop in 5C steps toward 200-210C and watch whether the wisps shrink. Hotter plastic is thinner and oozes more freely, so a small temperature reduction often clears stringing on its own without hurting layer adhesion. The fastest way to find your sweet spot is a temperature tower, which prints the same shape at several temperatures so you can pick the lowest one that still bonds cleanly.
2. Set retraction correctly for your extruder
Retraction pulls filament back to relieve pressure at the nozzle during travel, and the right amount depends on your extruder type. Bowden setups (most Ender 3, CR-10 and similar machines) need a longer pull, typically 4-7mm at around 40-60mm/s. Direct-drive machines (Bambu Lab X1/P1/A1, Prusa MK4, most modern printers) need far less, usually 0.5-2mm at around 30-40mm/s. Adjust the distance in 0.5mm increments and reprint a test after each change. On Bambu Lab printers keep retraction at 2mm or under, since over-retracting can pull molten plastic up and cause clogs.
3. Dry the filament
If temperature and retraction are dialed in and you still get strings, the filament is almost certainly wet. PLA absorbs moisture from the air, and that water turns to steam in the hot end, creating constant pressure that oozes plastic no matter how you tune retraction. Dry PLA at roughly 45-55C for 4-6 hours in a filament dryer or a low oven, then store it with desiccant in a sealed container. This single step is the most overlooked stringing fix.
4. Increase travel speed and enable wipe
The faster the nozzle crosses an open gap, the less time any ooze has to stick and stretch into a string. Raising travel speed to 150mm/s or more helps the head outrun the ooze. Enabling “wipe while retracting” makes the nozzle move slightly during the retraction so it cleans itself against the print rather than leaving a blob. In Bambu Studio and similar slicers, turning on “avoid crossing walls” also routes travel moves around open areas so fewer strings are even possible.
5. Run a retraction (stringing) test print
Rather than guessing, print a dedicated stringing test, usually two thin towers spaced apart so the nozzle must travel through open air between them. Change one setting at a time (temperature, then retraction distance, then travel speed), reprint, and compare. This isolates the real cause for your specific printer and filament instead of stacking changes blindly, and it is the single most reliable way to get to clean, string-free prints.
6. Check the nozzle and PTFE tube
Worn or partially clogged hardware can mimic stringing that no setting will fix. A nozzle with internal wear or buildup drools inconsistently, and on Bowden or hybrid hot ends a PTFE tube that no longer seats tightly against the nozzle leaves a gap where plastic collects and oozes. Inspect the nozzle, swap it if it is old or damaged, and make sure the PTFE tube is cut square and pushed fully home before you blame your slicer settings.
Frequently asked questions
What temperature stops PLA stringing?
Most PLA strings less at the cooler end of its range, so try 200-210C and drop in 5C steps. The exact number varies by brand, which is why a temperature tower is worth printing.
Does wet PLA cause stringing?
Yes. Absorbed moisture turns to steam in the hot end and forces plastic out continuously, so even perfectly tuned retraction will not fully stop it. Drying the spool usually solves it.
How much retraction should I use for PLA?
Use 4-7mm for Bowden extruders and 0.5-2mm for direct-drive extruders. Tune in 0.5mm steps with a test print, and keep Bambu Lab retraction at 2mm or under to avoid clogs.
Is stringing the same as oozing?
They are closely related. Oozing is plastic leaking from the nozzle when it should not; stringing is that ooze getting dragged into visible strands during travel moves. The same fixes address both.