How to Stop Your Prints Stringing

Stringing is molten plastic leaking from the nozzle while the head moves between two parts of the model, leaving a fine hair behind. It is almost always cosmetic — the part is structurally fine and the hairs brush off — but on a model with lots of separate towers or lettering it is the difference between a print you show people and one you do not.

Fix 1: dry the filament

Water absorbed from the air turns to steam inside the hot end. Steam pushes plastic out of the nozzle when nothing is supposed to be coming out, which is precisely the mechanism that creates strings. It also produces popping and crackling sounds while printing and a rough surface finish.

The manufacturers are consistent about this. Polymaker states on its PETG page that the material is very hygroscopic and that wet PETG leads to stringing and poor surface quality, and publishes 60 °C for 6 hours as the fix. Overture publishes 60 °C for 5 hours and warns against over-drying, which makes filament brittle. Bambu Lab lists “dry out before use” in its own cautions for PETG.

PLA absorbs more slowly than PETG and TPU but it does absorb. A spool left open on a shelf for a month in a humid room will string when the same spool did not when it was new. The full treatment — including whether you need a dryer or just a sealed box — is on filament storage and drying.

Fix 2: lower the nozzle temperature, 5 °C at a time

Hotter plastic is runnier, and runnier plastic leaks more readily out of a nozzle that is not being asked to extrude. If the spool is dry and it still strings, this is the next lever.

Move in 5 °C steps and stay inside the published range on the spool. Overture publishes 190-220 °C for its PLA and 230-260 °C for its PETG; Polymaker publishes 240-260 °C for PETG. There is room in every one of those ranges to come down without leaving the manufacturer’s specification.

Watch layer adhesion as you go. Too cold produces a part that looks clean and splits along the layer lines when you load it, which is a worse failure than a hair you could have brushed off.

Fix 3: check retraction, but check it second

Retraction pulls filament back up the nozzle before a travel move so there is less pressure behind the melt. It is the setting every guide leads with and the third thing we would touch, because the modern machines in this site’s beginner picks ship with retraction already tuned by the manufacturer for their own hardware. Changing it blind on a machine whose profile was tuned for you is how people spend an evening making things worse.

If you do adjust it, note that the correct figure depends on the extruder type, and manufacturers publish both. Polymaker, for example, publishes 1 mm at 20 mm/s for a direct-drive extruder and 3 mm at 40 mm/s for an indirect-drive one — a threefold difference, and proof that a number copied from someone else’s machine is meaningless.

Fix 4: raise travel speed

A faster travel move gives leaking plastic less time to fall. This is a genuinely effective and frequently overlooked adjustment, and it costs nothing in quality — travel moves are not printing, so moving faster during them affects nothing else about the part.

Fix 5: turn on combing or wipe

Most slicers can keep travel moves inside the already-printed area of the model, so any leak lands on a surface that is going to be covered anyway. Look for “combing,” “avoid crossing perimeters” or “wipe while retracting” depending on which slicer you use. It does not stop leaking; it hides it where it does no harm.

Fix 6: clean or replace the nozzle

Residue on the outside of the nozzle drags along the print and can deposit material where you do not want it, which looks like stringing and is not. A worn nozzle also produces inconsistent flow that shows up the same way. Both are covered in order on the clogged nozzle page.

When to stop tuning

At the point where the hairs brush off with a fingernail and do not come back on the next print. Perfect zero-stringing prints exist, mostly on dry filament in a stable room, and chasing the last one percent is how a hobby turns into a second job. A quick pass with a heat gun on low, or a fingernail, removes what remains on most models.

If your prints are failing rather than looking untidy, this is the wrong page — start at prints not sticking to the bed, which covers the failures that lose you the whole part rather than the finish.