Bad quality at horizontal faces I'm newbie at this stackexchange and I have a "FlashForge Finder"; lately there are many problems with the horizontal surfaces quality (Bottom and Top at the same time).

As some issue guides suggests, I changed: number of solid layers, % of filling and extrusion multiplier; I use "Flashprint", so some concepts must be translated from Cura in the options menu.

P.S: All filaments are PLA.

Without any change:



After all changes (the "best")


My settings for last black disk:
This could be caused by under extrusion, often caused by the bed being too close to the hot end / extruder nozzle. You could try to relevel the bed, or change the screws so that the bed moves down slightly. Often when levelling, you want to feel slight resistance when sliding a piece of paper between the bed an the nozzle. You should do this for all 4 corners. Be careful though, you dont want the bed too far away from the nozzle, or problems maybe arise with the print not sticking to the bed.

Hope this helps, Luke.