HOW TO USE VARIABLE (ADAPTIVE) LAYER HEIGHT

Variable layer height (also called adaptive layer height) varies the layer thickness throughout a single print. The slicer scans the model's geometry: where the surface is mostly vertical (flat walls), it uses thick layers (e.g., 0.28 mm); where the surface is curved or angled (where stair-stepping would show), it uses thin layers (e.g., 0.12 mm). The result is detailed surface where it matters and a faster print where it doesn't. The technique is supported in PrusaSlicer, OrcaSlicer, and Bambu Studio. Cura supports a similar feature ('Adaptive Layers') with less control. Typical print time saving: 20-40% versus a fixed thin layer height, with similar visual quality.

Use variable layer height when: the model has both detailed curved features and large flat or vertical surfaces (busts, figurines with bases, organic shapes with flat backs). Or when you want max detail without doubling print time. Don't use when: the model is uniformly detailed throughout (a fully sculpted miniature - all features are detailed). Or uniformly flat (a flat panel - no benefit from varying). Or for mechanical parts where layer height needs to be predictable for strength calculations.

PrusaSlicer: 1. Load the model. Set base layer height to your typical max (e.g., 0.28 mm). 2. Right-click the model in the 3D view - Variable Layer Height. 3. A side panel opens with a slider showing layer height per Z position. 4. Click 'Adaptive' button - PrusaSlicer auto-generates a layer height profile based on geometry. 5. Adjust the 'Quality / Speed' slider: - More toward 'Quality': more thin layers, slower print, smoother curves. - More toward 'Speed': fewer thin layers, faster print, slight stair-stepping on curves. 6. Manually paint over specific Z regions with thicker or thinner layers using the brush tool, if needed. 7. Slice and check the preview - layer count and time should drop versus uniform thin layers. OrcaSlicer / Bambu Studio: 1. Load model. 2. Quality - Adaptive Layer Height. 3. Toggle on. Set base layer height to max (0.28 mm). 4. Set 'Adaptive layer thickness' range: typical 0.08 mm min to 0.28 mm max. 5. Slicer auto-generates the variable height profile. 6. Slice and inspect. Cura (Adaptive Layers - more limited): 1. Quality - Adaptive Layers (in Experimental settings). 2. Adaptive Layers Topography Size: smaller = more variation, larger = simpler. 3. Adaptive Layers Maximum Variation: how much layer height can change. General settings to verify: - Min layer height: usually 0.08-0.12 mm (depends on nozzle / printer). - Max layer height: usually 75% of nozzle (0.30 mm for 0.4 nozzle). - Smoothing: enabled (avoids abrupt layer height changes that cause visual banding).

Setting min layer height too low. 0.04 mm on a 0.4 mm nozzle = poor extrusion. Stick to 25% of nozzle as min. Setting max layer height too high. Above 75% of nozzle, layer adhesion suffers. Stick to 0.30 mm max for 0.4 nozzle. Variable layer on functional parts. Layer thickness changes between layers, which means strength varies subtly across the print. For mechanical parts where consistency matters, use uniform layer height. Not previewing the slice. Variable layer can produce surprising profiles. Check the preview to confirm thin layers are where you want them. Using on small detailed prints. A miniature might need uniform 0.08 mm everywhere - variable adds no benefit and might leave thicker layers on detail you wanted detailed.

Pairs naturally with how-to-choose-layer-height. For models with mixed detail and flat regions, this is the ideal solution. For a uniform max-quality print, see how-to-choose-layer-height for picking a single thin value.