Odd print artifacts on same layer as large top surface I printed the following object (I'm printing the single opening version, Flower_pot_3.STL), and observed an unusual print artifact. I would like some idea of what's going on so I can avoid it in the future. The object is essentially an open-top box. In the image below, you can see a ridge along the bottom of the print. This corresponds to the upper surface of the bottom side of the box. The ridge is present for 4 layers, the same number of layers on the top surface. The defect is basically a positive ridge all the way around (not a layer shift). The G-code render below is for the top layer of the bottom surface.

System Settings


Printer is Prusa Mk3, with white PLA plastic. Nozzle is HS steel at 210&nbsp;&deg;C
0.2&nbsp;mm Layer height, 15&nbsp;% Gyroid infill, 3 perimeters
Perimeters are printed first each layer, with the outer perimeter coming last.
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Ideally, I would like to know what caused this artifact, and what I could do to avoid it in the future. I can add more information as requested.
Just a guess here. If I understood correctly the deformation is at the first layer of the box bottom, it seems highly unlikely that it randomly happened at this exact position so I am assuming that if you do the print again you will get the same deformation at the same place (you can test this maybe ? I know it is a long print). In this case it is more likely that is a slicer issue than something with your machine and it could also be a problem with the stl model. Maybe try to create a small simple box then slice it using the same setting and try to see if you can reproduce artifact.