Does layer height affect quality? What thinner layers change, and what they cost

Yes. Thinner layers shrink the steps on curves and slopes and let overhangs print flatter without support. They cost print time, not filament: 0.08 mm took 2.18 times as long as 0.20 mm in Bambu Lab’s example. Detail across the bed, such as text lying flat, doesn’t change.

Does layer height affect print quality?

Yes. Every curve and slope prints as a staircase with steps one layer tall, so 0.08 mm layers leave steps less than a third the height of 0.28 mm ones. The gain shrinks below 0.10 mm: Prusa calls the improvement from 0.07 or 0.05 mm layers relatively minor for significantly longer prints.

Bambu Studio’s presets for the Bambu Lab X1 Carbon with a 0.4 mm nozzle describe the trade in their own words:

Layer height	Preset	Bambu Lab’s description
0.08 mm	Extra Fine	Almost negligible layer lines, longer printing time
0.12 mm	Fine	Almost negligible layer lines, higher quality, longer time
0.16 mm	Optimal	Less apparent layer lines, higher quality, longer time
0.20 mm	Standard	General layer lines and quality, for most general printing
0.24 mm	Draft	More apparent layer lines, lower quality, slightly shorter time
0.28 mm	Extra Draft	More apparent layer lines, lower quality, shorter time

Where thinner layers show most

Thin layers pay off most on domes and nearly flat tops. Each step on a slope is one layer tall and layer height ÷ tan(slope) wide (0.20 ÷ tan 10° = 0.20 ÷ 0.176 = 1.13 mm), so flatter surfaces get wider steps. Bambu Lab’s wiki notes the same.

Surface angle from horizontal	Step width at 0.08 mm	At 0.20 mm	At 0.28 mm
10°	0.45 mm	1.13 mm	1.59 mm
30°	0.14 mm	0.35 mm	0.48 mm
60°	0.05 mm	0.12 mm	0.16 mm

To thin the layers only where they show, use variable layer height. Bambu Studio and PrusaSlicer both have an Adaptive button that sets layer heights from a detail (or quality) versus speed slider. In Bambu Studio it stays within the printer’s limits: 0.08 to 0.28 mm on a 0.4 mm nozzle.

Layer height for detail

Thinner layers add detail only in height. Prusa’s example: embossed text lying flat on the bed looks the same at any layer height. For finer detail across the bed, Prusa points to a smaller nozzle (see layer height for a 0.2 mm nozzle).

Choosing a layer height for good quality

1. Start at 0.20 mm on a 0.4 mm nozzle, Bambu’s preset for most general printing. Set it under Process > Quality > Layer height in Bambu Studio, or Print Settings > Layers and perimeters in PrusaSlicer.
2. Drop to 0.12 or 0.16 mm when curves or shallow slopes show steps.
3. Stop at 0.10 mm. Prusa doesn’t suggest going lower.
4. Stay between 20% and 80% of the nozzle, the OrcaSlicer wiki’s range: 0.08 to 0.32 mm on a 0.4 mm nozzle. The layer height calculator gives the range for any nozzle, plus the heights that land on whole motor steps.

Layer height also changes strength: see which layer height is strongest for the tensile tests.

How much faster do thicker layers print?

In Bambu Lab’s wiki example, 0.28 mm layers printed one model in 28 min 27 s against 36 min 14 s at 0.20 mm: about 29% fewer layers, 21% less time. At 0.08 mm it took 1 h 19 min, 2.18 times as long for 2.5 times the layers.

Layer height	Layers, vs 0.20 mm	Print time	Time, vs 0.20 mm
0.08 mm	2.5	1 h 19 min	2.18
0.20 mm	1	36 min 14 s	1
0.28 mm	0.71	28 min 27 s	0.79

Why time doesn’t follow the layer count

Taller layers run slower. Bambu Lab’s wiki explains why: a tall layer pushes more plastic, so the hotend needs a slower speed to melt it fully. The X1 Carbon presets on that page:

Speed	0.08 mm Extra Fine	0.20 mm Standard	0.28 mm Extra Draft
Outer wall	200 mm/s	200 mm/s	200 mm/s
Inner wall	350 mm/s	300 mm/s	200 mm/s
Sparse infill	450 mm/s	270 mm/s	200 mm/s
Internal solid infill	350 mm/s	250 mm/s	200 mm/s

Infill gains almost nothing from taller layers. Plastic per second is line width × layer height × speed: on Bambu’s 0.45 mm infill lines, 0.45 × 0.20 × 270 = 24.3 mm³/s at 0.20 mm and 0.45 × 0.28 × 200 = 25.2 mm³/s at 0.28 mm. Both exceed Bambu PLA Basic’s 21 mm³/s Max volumetric speed, and Bambu Studio caps print speed there, so both extrude at that same rate. Outer walls keep 200 mm/s in all three presets, so they gain the most.

If your profile keeps the same mm/s at every layer height, halving the layer height doubles the time spent extruding. The print time calculator scales your measured rate that way. For one model, slice it at both heights for the real answer.

Does layer height affect filament usage?

Barely. The same model sliced at 0.08 mm or 0.28 mm has the same shape, walls and infill, so it takes about the same plastic. What changes is the top and bottom skin, set as a layer count: Bambu Studio’s three bottom layers are 0.60 mm thick at 0.20 mm and 0.84 mm at 0.28 mm.

Bambu Studio preset	Top skin	Bottom skin
0.08 mm Extra Fine	9 layers, raised to at least 0.8 mm	7 layers, 0.56 mm
0.20 mm Standard	5 layers, 1.00 mm	3 layers, 0.60 mm
0.28 mm Extra Draft	4 layers, 1.12 mm	3 layers, 0.84 mm

All three keep 2 wall loops and 15% sparse infill. Moving from 0.20 mm to 0.28 mm adds 0.12 mm of top skin and 0.24 mm of bottom skin. Under a 20 × 20 mm top and bottom, that is at most 20 × 20 × 0.36 = 144 mm³, or 0.18 g of PLA at 1.24 g/cm³.

PrusaSlicer also counts skins in layers: 3 top layers at 0.3 mm make the same skin as 9 at 0.1 mm, per Prusa’s example. To hold the skin fixed when you change layer height, set a thickness:

• PrusaSlicer: Print Settings > Layers and perimeters > Horizontal shells > Minimum shell thickness.
• Bambu Studio: Process > Strength > Top/bottom shells > Top shell thickness and Bottom shell thickness. Bambu’s tooltip says this avoids a too-thin shell at small layer heights.

Does layer height affect overhangs?

Yes. Thinner layers let an overhang lean further out unsupported, because each layer sticks out less past the one below, per the OrcaSlicer wiki. Bambu Studio’s presets put numbers on it: with auto supports on, they support surfaces flatter than 15° from horizontal at 0.08 mm, 30° at 0.20 mm and 40° at 0.28 mm.

Preset	Support threshold angle	Step per layer at that angle
0.08 mm Extra Fine	15°	0.30 mm
0.12 mm Fine	20°	0.33 mm
0.16 mm Optimal	25°	0.34 mm
0.20 mm Standard	30°	0.35 mm
0.24 mm Draft	35°	0.34 mm
0.28 mm Extra Draft	40°	0.33 mm

At every preset’s threshold, each overhang layer sticks out 0.30 to 0.35 mm past the one below, less than one 0.42 mm line. That step is layer height ÷ tan(angle), for example 0.20 ÷ tan 30° = 0.35 mm. A thinner layer reaches the same step at a flatter angle.

Supports are off in Bambu’s presets. Turn them on under Process > Support > Enable support; Threshold angle sits in the same group, and a larger angle adds more support. To print one overhang without support, thin the layers only around it with variable layer height.

Does layer height affect tolerance?

Only in height. A part ends within half a layer of the model’s height: 0.04 mm at 0.08 mm, 0.10 mm at 0.20 mm and 0.14 mm at 0.28 mm. Bambu Studio stacks whole layers and keeps the top one only if the model is taller than that layer’s middle. Holes and clearances across the bed don’t change: Prusa’s knowledge base says layer height changes only the vertical resolution.

Bambu’s wiki example is a 2 mm cube at 0.24 mm layers on a 0.2 mm first layer: 0.2 + 7 × 0.24 = 1.88 mm, 0.12 mm short. Two ways to fix it:

• Precise Z height (Process > Quality > Precision, Bambu Studio 1.9 and later) adjusts the last 5 layers so the part ends at 2 mm. Bambu calls it experimental. It doesn’t apply below 6 layers or when it would break the layer height limits.
• Pick a layer height that divides the height that matters. At 0.20 mm, (2 − 0.2) ÷ 0.20 = 9 layers exactly.