GLOSSARY
Layer Height
Layer height is the vertical thickness of each printed layer, in millimeters. Smaller layers mean finer detail and more print time; larger layers mean faster prints and visible layer lines.
Definition
When you slice a 3D model, the slicer cuts it into horizontal slabs and prints each one in turn. Layer height is the slab thickness. On FDM, common values are 0.12mm (fine), 0.20mm (default), and 0.28mm (fast). On MSLA resin, 0.025–0.05mm is typical because the LCD can resolve much finer detail.
Layer height has to be smaller than the nozzle diameter on FDM — a 0.4mm nozzle can do up to roughly 0.32mm layers. Going below 0.08mm is rarely worth the print time.
Why it matters
Layer height is the master quality-vs-time knob. Halving the layer height roughly doubles the print time. For visual prints where surface finish matters, drop it. For functional parts where dimensions matter more than appearance, keep it at the default.
On angled surfaces, layer height shows up as stair-stepping. The shallower the angle, the more obvious the step. Designers often orient parts so the most visible faces are vertical (parallel to Z), which hides layer lines almost entirely.
Common confusion
Smaller layers do not always look better. Below about 0.10mm on FDM, gains diminish — the limit becomes nozzle width and material flow consistency, not Z-axis resolution. Use 0.12mm or 0.16mm for quality prints; 0.05mm is overkill for filament.
Variable layer height (adaptive layers) is supported in PrusaSlicer and OrcaSlicer — thin layers on curved sections, thicker layers on flat ones. Worth enabling for visual prints.