When your 3D printer’s head needs to reposition from one point in your model to another, the filament might ooze. The result is stringing: small strings of material appear between the printed parts. Stringing especially occurs with models that have big open spaces, but there are ways to avoid it.

The right material
Whether stringing occurs, varies per material. For instance, ABS hardly causes strings but PET-G does. The material composition also has an effects, so the extend of stringing may differ per supplier.

Retraction setting
It’s possible to activate the retraction setting in the slicer software. This functionality makes the filament retract into the nozzle, before the print head moves to a different part of the product. The retraction speed is also important, when it’s set too low strings may still appear.

Wipe nozzle setting
This option can be combined with the retraction setting. With wipe nozzle, the printer will wipe the last bit of liquid material onto the model before the filament is retracted and the print head moves to its next location. This way, threads will be minimized even further.

Temperature
When the filament still oozes after retraction, the printing temperature might be set too high. The material then becomes very fluid, which makes retraction harder to execute. Check the settings with your filament supplier and adjust the temperature when necessary.

Movement speed
The bigger the distance between two points within the model, the harder it is to retain the filament in the nozzle. For a model with big gaps, we therefore recommend to increase the movement speed a little. The movement speed is not the same as the printing speed, because it concerns the movement between printing points. Note that the speed shouldn’t be set too high either, because then the pint head might overshoot, causing displacements in the model. So, look for the right balance.

Is the product still not perfect? Your last option is the finishing: you can clear the model of the last strings with a heat burner or a hairdryer.