Fighting Stringing Part 2: Calibrating retraction settings

Fighting fine stringing is one of the most frustrating problems to pin down, and our slicers provide numerous work-arounds to help us deal with this problem:

  • retraction and de-retraction length

  • retract/de-retract filament speeds

  • wiping

  • z-lift or z-hop

  • coasting (Cura)

Unfortunately, the testing process can be a long and tedious process. It is particularly frustrating to test individual small prints with different printer settings such as retraction.


Be sure you’ve calibrated your slicer filament settings before trying to find the perfect retraction settings. Retraction and related settings are work-arounds for imperfect extrusion results. Calibrate your filament settings first to match your slicer extrusion settings to your real-world printer and filament settings first to reduce the number of work-arounds required to get good results.

One trick is to use a “virtual multi-extruder” printer profile to create a multi-part single print with unique hardware settings for each part.


These notes are based on my experiences with the Prusa i3 Mk3 and Artillery/Evnovo Sidewinder X1 printers. If you are using a different printer, please verify the hardware details are similar.

The idea is to create a printer profile with multiple extruders and enter different settings for each extruder. Assign each part to a different extruder and you can (with a bit of patience) generate several tests with a single print as shown below.

Retraction calibration print

Fig. 86 Retraction calibration print

It’s a little cumbersome, but it beats trying to track multiple tiny prints. Here’s an example showing several retraction setting modifications:

  • Retraction length is set to 0.2mm

  • Lift Z is set to 0mm

  • Retraction speed is set to 50mm/s

  • Deretraction speed is set to 25mm/s

Extruder settings

Fig. 87 Extruder settings

Provided each part is small enough, you can produce a single print that compares multiple settings.

Retraction calibration print results

Fig. 88 Retraction calibration print results

You can download a project file for testing PETG with a 0.60mm nozzle here. (Fixed nozzle size. Thanks @ido.d)

I use the following retraction settings as a starting point:

  • 0.2-0.4mm retraction

  • 0-0.2mm z-lift

  • 50mm/s retract speed

  • 25mm/s de-retract speeds

Contact and feedback

You can find me on the Prusa support forums or Reddit where I lurk in many of the 3D printing-related subreddits. I occasionally drop into the Official Prusa 3D discord server where I can be reached as bobstro (bobstro#9830).

Last updated on 20200131