Infill Density and Patterns

Theoretical Background and Structural Mechanics

The interior of an FDM printed part behaves similarly to open-cell or closed-cell foams, which are mathematically modeled as cellular solids. The mechanical behavior of these structures depends on the topology of the lattice and the volume fraction of the solid material.

1.1 Infill Density vs. Volume Fraction

Infill density is expressed as a percentage ($0\%$ to $100\%$). From a mechanical standpoint, this corresponds to the relative density or volume fraction ($\varphi$):

Infill Patterns Deep Dive

OrcaSlicer classifies infill patterns into three primary categories based on their dimensional geometry and mechanical behavior: 2D patterns, 3D (Isometric) patterns, and Flexible/Specialized patterns.