Short answer
For most functional parts, 0.20 mm layers with standard infill is the right answer and you can stop reading. Go coarser (0.30 mm) for early prototypes and hidden parts; go finer (0.12 mm) only when a surface will be seen or a small feature needs definition.
What layer height actually controls
Layer height is how thick each printed slice is. It sets three things at once: how visible the layer lines are, how long the print takes, and how well small details resolve.
| Setting | 0.30 mm | 0.20 mm | 0.12 mm |
|---|---|---|---|
| Print time | Fastest | Middle | ~2× slower |
| Layer lines | Clearly visible | Visible, tidy | Barely visible |
| Small detail | Softened | Good | Sharp |
| Strength | Slightly better | Good | Marginally weaker |
The strength column catches people out. Thicker layers are usually slightly stronger, because there are fewer bonds between layers for a crack to travel along and each bond is fatter. Fine layers look better and cost more; they do not make a part tougher.
When fine layers are worth paying for
Only two situations really justify 0.12 mm. The first is a visible cosmetic surface — something a customer will look at closely, or a part that has to sit alongside a moulded original without looking obviously printed. The second is genuinely small features: text under about 3 mm tall, shallow engraving, or a fine thread form that needs definition.
For a bracket bolted inside a cupboard, fine layers are money spent on something nobody will ever see.
What infill really does
Infill is the lattice inside the part. The outside is made of solid perimeter walls; infill supports those walls and gives the part its bulk stiffness. It is quoted as a percentage, and the relationship to strength is not linear.
Going from 15% to 30% infill adds a lot of stiffness for a modest amount of extra material. Going from 50% to 80% adds relatively little strength for a great deal of plastic and time. Past about 60%, you are usually better off adding a wall or a rib than adding infill.
Walls matter more than infill
If you take one thing from this guide, take this. For most loads, the perimeter walls carry the force and the infill just stops the walls buckling inward. A part with three perimeters and 25% infill is typically stronger than the same part with two perimeters and 50% infill, and uses less plastic.
That is why our quality settings adjust infill alongside layer height rather than exposing infill as a separate dial — the combinations that actually make sense are fewer than the settings menu suggests.
Sensible defaults by job
- Early prototype, checking fit — 0.30 mm, low infill. Fast and cheap; you are testing dimensions, not durability.
- Working functional part — 0.20 mm, standard infill. The default for a reason.
- Load-bearing bracket — 0.20 mm, and design in thicker walls rather than asking for more infill.
- Visible or cosmetic part — 0.12 mm, and consider orientation carefully so the good face is not covered in support marks.
Common questions
What layer height should I choose?
For most functional parts, 0.20 mm. Go coarser at 0.30 mm for prototypes and hidden parts, finer at 0.12 mm only when a surface is visible or a detail is small.
Does higher infill make a part stronger?
Much less than people assume. Beyond standard infill the gains are small while weight, time and cost all climb. Thicker outer walls do far more for strength.
Do finer layers make a part stronger?
No, marginally weaker. Each layer bonds over a smaller area, so more layers means more interfaces. Finer settings buy appearance and detail, not strength.
How much more does a fine finish cost?
Roughly double the machine time against the standard setting, so expect a noticeable jump. The quote tool shows all three settings priced so you can compare before choosing.
Will I see the layer lines either way?
Yes, at every setting. At 0.12 mm they are hard to spot at arm’s length; at 0.30 mm the surface reads as clearly printed.
Do I need to choose infill myself?
No. Infill is set sensibly for you at each quality level. If your part has an unusual load case, tell us and we will adjust it.
What this means when you order
The quote tool shows all three quality settings with live prices, so you can see exactly what finer layers cost before choosing. Infill is handled for you at each setting.
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Published 7 September 2026 · last reviewed 5 October 2026.