The build surface needs to be level to ensure the filament properly sticks to the surface and to provide a secure foundation for the print job. The bed can be leveled by either mechanically leveling the bed or using a raft to accommodate for unevenness.

• Mechanical Leveling - The easiest way to check this is to command the printer to "zero" the axis and move the extruder to its lowest position. You should be able to insert a sheet of paper between the build platform and the tip of the nozzle. If there is a gap, gently raise that side of the build platform using the adjustment screw or a shim and continue checking the remaining corners of the build area.
• Extrusion Raft - If the build platform is warped, or cannot be leveled, try printing your next object with the "raft" feature enabled. This will deposit a thick grid of material onto the bed at the beginning of each print and will eliminate most adhesion problems.