Why is this single layer of support interface showing up?

There is a setting (“avoid interface filament for base”) that should do that: Bambu Studio 1.8.2 Release Notes | Bambu Lab Wiki.

I did a swift test and couldn’t replicate the results shown in the post, and also it is intended for other purposes.
I can try to explore further later and come back to you if I find something new.

You can change the type of pattern and distance (density). That base pattern is also present if you don’t use a support material; in my experience, it seems to work well.

1 Like