3D printer prints random lines on print.

[fiftyone]

Dear reader,

First of all, my name is Roel, and I am new to 3d printing. I purchased my first 3D printer (Ender 3 V2) about two weeks ago. I ran some prints, mainly printer upgrades, and the results did not dissapoint me.

Now I tried to print my own drawing for the first time, and it went quite well. However, there were some strange vertical lines printed on it (see attached pictures). I use the ender 3 v2 with 0.4 mm nozzle, with eSUN PLA+ black filament, nozzle temp 210 degrees C and bed temp 60 degrees C. Does anybody know where these lines come from, and how to get rid of them?

Thanks!