Layer Height

Theory

Layer height is the primary resolution parameter in FDM printing. It is constrained to be between 25% and 75% of the nozzle diameter for reliable extrusion and adhesion. With a 0.4 mm nozzle, the practical range is 0.1-0.3 mm; 0.2 mm is the standard. Lower layer heights produce smoother surface finish (fewer visible ridges) and better detail in the Z-direction, but exponentially increase print time. Higher layer heights print faster but produce coarser staircase effects on curved surfaces.

Application

Use 0.1-0.15 mm for fine miniature detail or prototype aesthetics. Use 0.2 mm as the standard workhorse setting. Use 0.25-0.3 mm for structural or time-critical prints where aesthetics are secondary. Enable adaptive layer height in the slicer to automatically reduce layer height on curved surfaces and increase it on flat vertical faces for optimal speed/quality balance.

Common mistakes

Layer height above 75% of nozzle diameter causes poor layer adhesion and extrusion inconsistency. Below 25% of nozzle diameter the bead is so thin it loses structural integrity. Adaptive layer height on organic shapes can create unintended layer height jumps at geometric transitions that appear as surface artefacts. Always re-check first-layer calibration when changing layer height as the absolute gap changes.

Related terms: Nozzle, Extrusion Width, Top and Bottom Layers