Lattice basics
A lattice is a three-dimensional network of thin struts that repeats through a volume. In 3D printed footwear it takes the place of foam: it cushions by bending, and it is open, so air and water pass through.
How a lattice cushions
Foam cushions by squeezing small gas-filled cells. A lattice cushions by bending and buckling its struts. Because the geometry is designed rather than foamed, the designer can decide how soft each zone is: thinner struts or larger cells give a softer feel, thicker struts or smaller cells a firmer one, all in the same material and the same printed part.
The three variables that matter most
| Variable | If it increases | Effect on the wearer |
|---|---|---|
| Cell size | Fewer, larger openings | Softer, springier, more airflow; less even support |
| Strut thickness | Each strut is stiffer | Firmer and more durable; heavier |
| Material hardness | The polymer itself is stiffer | Firmer overall, at every point |
Common cell shapes
- Strut-based cells (cubic, octet, honeycomb-style): simple to design and inspect; straight load paths make them feel springy.
- Surface-based cells such as the gyroid: smooth curved walls with no sharp joints, which spread stress evenly and tend to be durable.
- Irregular cells based on a Voronoi diagram: cell size can change gradually across the foot, which makes zoning easy. Our Voronoi reference design uses this.
Airflow and water
Because a lattice is open, it breathes and drains in a way closed foam cannot. How open the top surface is can be described with our PFL Vent Score; how finely it is divided, with the PFL Strut Density. A very open lattice also lets grit in, so it needs rinsing more often.
How lattices wear
Foam tends to flatten slowly as its cells break down. A lattice usually keeps its shape until individual struts start to crack, most often at joints that bend the most. Smooth joints, surface-based cells and a tough elastomer all extend life. Our PFL Rebound Index describes one simple way to compare how well a lattice recovers after a load.
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