Layer height: quality against time, and when fine is not worth it
What changes between 0.12 and 0.28 mm, why a fine layer doubles the price, and on which parts the difference genuinely shows.
Layer height is the thickness of each band of plastic the machine lays down. It is the option that most changes how a part looks and the one that most changes the price, and the two are linked: making the same part with finer layers means making more layers, and each layer costs time.
The relationship is close to linear
Going from 0.28 to 0.14 mm doubles the number of layers, and therefore very nearly doubles the print time. Since machine time is one of the two halves of the price, a part at a fine layer height can cost close to twice the same part at a coarse one. The material does not change: it is exactly the same plastic.
Where it shows and where it does not
- It shows a lot on gently curved surfaces and shallow slopes: that is where the stepping is visible and tangible.
- It shows on small detail: text, embossing, fine edges. A coarse layer swallows them.
- It barely shows on vertical walls and flat faces. There, a fine layer is money thrown away.
- It does not change accuracy in X and Y. A hole does not come out rounder with a finer layer: that is a different matter.
What to choose
| Part | Layer | Why |
|---|---|---|
| Form prototype, fixture, fit test | Coarse | You only want to know whether it fits. Fast and cheap. |
| Functional part that stays hidden | Standard | Nobody looks at it. The standard is just as strong. |
| Enclosure, handle, something handled | Standard or fine | Depends on whether it gets sanded afterwards. |
| Model, figure, merch, presentation | Fine | Here, appearance is the product. |
If appearance matters most, there is a shortcut: resin. Its layers are so fine that stepping practically does not exist, without paying the time it would take to get there in FDM.