Glossary · Failure pattern

3D printing

Stringing

Fine plastic threads between separate parts of the print that look like cobwebs.

Explained in more detail

Occurs when molten plastic runs out of the nozzle during travel moves. Main causes: nozzle temperature too high, too little or too slow retraction, damp filament. Countermeasures: lower the temperature in steps of 5 degrees, calibrate retraction, dry the filament, and avoid travel moves over outer walls in the slicer. PETG and TPU are more prone to it than PLA.

Where does the term come from?

English "string" means thread or cord, so "stringing" is the drawing out of threads. Because of its appearance, people also talk about cobwebs or hairs on the print.

In practice

• Damp filament is the most common cause, recognisable by crackling, small bubbles and a rough surface.
• With a temperature tower you find the lowest temperature at which the layers still hold well.
• In the slicer, enable "Avoid crossing walls" and raise the travel speed slightly.
• Fine hairs on PETG and TPU are normal and can be removed in seconds with a heat gun.
• Change only one setting per test print, otherwise you will not know in the end what helped.

Not to be confused

Stringing is not the same as over-extrusion: strings occur during travel moves between separate areas, whereas with over-extrusion walls and surfaces are too thick overall.

Frequently asked questions

How do I get rid of stringing with PETG?

Dry first, then lower the temperature in steps of 5 degrees and check the retraction, usually 0.5 to 1.5 mm with direct drive. A few fine hairs often remain with PETG anyway.

Why is my filament suddenly stringing?

It has usually absorbed moisture from the air. Drying fixes this in many cases without you having to change any settings.