The internal lattice structure printed inside a solid model to provide strength while minimising material use.
Infill is the internal lattice filling the volume between outer walls and top/bottom layers. Density is expressed as a percentage (0% = hollow, 100% = solid). Common patterns include grid, gyroid, honeycomb, and cubic. Gyroid provides isotropic strength; honeycomb excels at compression. Going from 20% to 40% adds only 10-15% tensile strength but significantly increases material use and time.
Use 15-20% infill for decorative parts, 40-60% for functional loads, 80-100% for maximum strength. Choose gyroid for flexible or impact-loaded parts. Increase infill near stress concentrations using modifier meshes. Align linear infill direction to the primary load axis for best structural efficiency.
High infill density dramatically increases print time with diminishing mechanical return. Too-low infill under top surfaces causes pillowing: increase top layer count or infill to at least 20%. Sparse infill combined with tall prints risks pillar collapse: use more perimeters instead.
Related terms: Wall / Perimeter, Top and Bottom Layers, Print Speed
| Field | 3D printing |
|---|---|
| Also called | infill density, infill pattern |
| Source | EDi Brain: tech/fdm |
Engineer, author of The Big Book of 3D Printing and additive manufacturing expert