Vertical empty strings when printing



can anyone say what error this printed image is due to?

black = amazon basic filament 1,75 pla
blue = eryone 1,75 pla

Hi,
It’s called banding. It’s very tricky to solve this problem.
Generally, you have to adjust the nuts on each Z-axis, but it’s very complicated to repair completely.

Kk, and what about the vertical empty String ?

Are you talking about the diagonal at the top?
I hadn’t seen it.
If so, I don’t know.
Have you checked the model?

i mean at the blue prints on the left side vertical from top to button, but i just found out that could be the seam from the 3d model! Sry… im completely new to 3d printing!

I understand.
You’re right, it’s the seam.
You can choose the position of this seam in the settings of you slicer

I’ve had similar artifacts created by having scarf joints turned on and not having the settings quite right.