Infill Patterns — Which One to Use and When

Infill pattern is one of those settings that makers spend a disproportionate amount of time optimising. There are articles dedicated to comparing gyroid vs. honeycomb vs. cubic subdivision. The differences in practice are real but narrower than the discourse implies.

For most applications — functional prototypes, enclosures, brackets, mounts — the infill percentage matters far more than the pattern. Going from 15% to 30% infill has a larger effect on part strength than switching from grid to gyroid at the same percentage.

That said, there are specific cases where pattern choice actually makes a meaningful difference. Understanding those cases is more useful than trying to find a universally optimal pattern.

Grid and lines: the defaults

Grid (rectilinear) and lines are the fastest to print and produce acceptable results for most applications. The material is laid down efficiently with minimal travel moves. Print time and material use are both optimised.

The weakness: grid and lines are anisotropic. They're strong in the directions the lines run and weaker perpendicular to them. For parts that are loaded in a predictable direction, you can orient the grid to align strength with load. For parts that see loads from multiple directions, a pattern with more isotropic behaviour is better.

Gyroid and cubic: when they're worth it

Gyroid infill has genuinely superior properties for parts that see compression from multiple directions or complex load cases. The interconnected curved structure distributes loads more evenly and resists delamination better than planar infills.

The cost is print time: gyroid is slower than grid at the same percentage, both because of the complex path and because gyroid doesn't bridge as efficiently in the Z direction.

When gyroid is worth using: parts under compression from multiple directions (3D-printed mounts that see loads in XYZ), flexible parts where you want consistent deformation behaviour, parts where the cross-section changes significantly along the print height.

Cubic subdivision is a compromise: more isotropic than grid, faster to print than gyroid. Good general choice when you want better than grid but can't afford the gyroid print time penalty.

Honeycomb vs. triangles: structural considerations

For parts under in-plane compression (think: a wall that gets compressed), triangulated infills distribute loads better than hexagonal honeycomb. Triangles are stiffer in compression. Honeycomb is lighter for the same density.

For most maker applications this distinction is irrelevant. It matters for load-critical structural parts where you're trying to maximise specific strength — the strength-to-weight ratio. Drone frames, load-bearing brackets at the edge of their capacity, structural components in competition robots.

The practical guidance: if you're printing something structural and weight matters, compare triangular infill at the minimum structural percentage against honeycomb at a higher percentage. The weight may be similar but the strength distribution differs.

The percentage-first rule

Before choosing a pattern, decide on the percentage. For most non-structural parts: 15–20% is sufficient. For structural parts under moderate loads: 30–40%. For high-load structural parts: 50%+ with careful wall count consideration.

Then choose the pattern: for non-directional loads, gyroid or cubic. For directional loads, align grid with the load direction. For weight-critical applications, experiment.

The default advice: start with grid at 20% for most things. Switch to gyroid if the part is under complex loading. Adjust percentage before adjusting pattern.