How to prevent scars on top surface?

I am using the stock nozzle
Tried adjusting z hop to 1.4mm with no change (see pic, line across the rectangular model). they all look like that.

Google Photos

I have also tried different temps, increasing retraction speed.

I am trying to get perfect PETG prints and bambu basic is giving me issues.

Wondering if this can be prevented so the nozzle stays cleaner and do not get the occasional blob.

Have you tried ironing?


I had a similar problem using the “Monotonic line” option for “Top surface pattern” in Strength menu, so i tryied to change this option to “Monotonic” and this reduced many scars on top surfaces.

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that is not the issue, the issue is that the scarring happens as it prints, collecting PETG on the nozzle.
As mentioned Z hop has been tested up top 1.4 mm with no effect.

I will try this and see how it goes

Are you sure that’s the root cause? How dry is your filament? Moisture can cause debris to collet on the nozzle as well. You could also add an additional wipe for the nozzle ever some many layers.