What is the strongest infill pattern?

At the same density there isn’t a dramatic winner. Grid and triangles are the most reliable all-rounders, hexagonal is very rigid but snaps suddenly, and gyroid fails slowly right where it’s loaded.

Is gyroid stronger than grid?

Gyroid is known as a strong infill, but the bigger difference is the failure. In Slant 3D’s crush test, gyroid only crushed where the load was, while grid cracked along a diagonal.

Which infill pattern is best for impact?

One that crushes gradually instead of snapping. In the test, gyroid and cubic crushed from the top down with no single catastrophic failure.

What is cross 3D infill for?

Filling a part with fewer retractions, which lowers the chance of a jam. It wasn’t reliable or strong in the crush test.

3D Printing3D Modeling / DFMBest infill pattern

Which infill pattern is strongest? Pick it by how it breaks

Slant 3D printed the same brick in every standard Cura infill, all at 25% in PLA, and crushed them one by one. No force numbers. That’s on purpose. The best infill pattern for strength isn’t about which brick survived longest. It’s about how each one broke when it finally went.

⚡ Rule of thumb

Use grid or triangles as the default; reach for gyroid or cubic when a part should crush gradually, and avoid hexagonal where a sudden snap would be a problem.

Starting point

Grid or triangles @ 25% · gyroid / cubic for a controlled crush

Measured

Infill pattern at equal density, judged by failure mode (crush vs. snap)

Confidence

Creator technique

▶ Source video — Learn How Infill Patterns Behave Under Stress — Slant 3Dwatch on YouTube ↗

Applies to

Process: FDM / filament
Test setup: Cura patterns, 25% density, PLA, crushed from the top
When: Picking a pattern for a part that takes real load
Not for: Most everyday parts, where the default is fine

Why it matters

A part that crumples slowly gives you warning. It dents, it deforms, it keeps sort of working. A part that snaps is fine, fine, fine, then in two pieces.

Same density, same plastic, and the patterns still split into those two camps. That’s the useful finding. Pick the pattern for how you need the part to fail.

Here’s what each one did under the press.

Grid crushed fairly steadily, but the failure ran along a diagonal until it broke through the outer shell. Triangles, the presumed favourite, had very good strength and crumpled at the top, predictably, until the wall gave and the part slid along the diagonal.

Zigzag looks dense, but its lines don’t cross from layer to layer, so it acts like internal suspension cables. It squashed more than it failed, and the layer lines separated. Lines behaved much the same, but crushed along the diagonal like grid.

Cubic, with its closed internal pockets, crushed at the top and worked its way down with no single catastrophic failure. Hexagonal, an evolution of the triangle, was strong and rigid. Then it failed all at once along the diagonal. When it goes, it goes.

Cross 3D was neither reliable nor strong; it exists to cut retractions. Gyroid crushed right where the load was, like a puncture, and nowhere else.

What good looks like

The pattern is the slicer default (grid or triangles) unless there’s a reason
Impact or crush-loaded parts use a pattern that fails gradually (gyroid, cubic)
Nothing safety-relevant relies on hexagonal holding, since it lets go all at once
The pattern choice is written down with the reason, so the next reprint matches

How to apply it

Start with grid or triangles. Slant 3D calls these the most reliable in most situations.
Ask how this part gets loaded: steady squeeze, impact, or bending.
If it should dent instead of shatter, try gyroid or cubic.
If rigidity matters most and a sudden failure is acceptable, hexagonal is very stiff.
Skip cross 3D for strength. Use it only when you just need to fill space with fewer retractions.
Print two candidates and crush them the way the part gets loaded. Watch where it starts.

Test it on your setup

Print two identical 20 mm cubes at 25%, one grid and one gyroid. Squeeze each in a vise and watch. One tends to crack along a diagonal; the other dents where the jaw touches it.

Exceptions & tradeoffs

Mind you, for most FDM parts this doesn’t matter much. Slant 3D says it plainly: most printed parts aren’t in high-performance roles. Leave the default and move on.

Pattern names and behaviour vary by slicer. These results are from Cura’s patterns. PrusaSlicer and Orca have their own versions with different line paths.

Cubic’s closed pockets don’t let air through. If you need airflow or a fill that liquid can reach, use an open pattern like gyroid.