Plastic extrusion, or fused deposition modeling (FDM) is the most common desktop 3D printer technology; FDM printers melt plastic and use an extruder to print each layer.
100 µ = 0.1 mm (highest resolution)
200 µ = 0.2 mm
300 µ = 0.3 mm
400 µ = 0.4 mm