Design Nomenclature / Physical Model Making

Print anisotropy

Also called layer-direction strength, Z strength, interlayer strength

A printed part is not one material — it is stacked welds. FDM strength across layers runs roughly half that along them, and the fracture always finds the layer plane. Orientation is therefore a structural decision made in the slicer, and it is the single most misunderstood thing about printed prototypes.

Section through a printed wall on the build plate, its courses drawn as separate rounded beads — a stack of welds rather than one material. One course line is picked out heavily in accent as the weak plane, kinked where the crack would run, with arrows above and below pulling apart across it. A second callout marks the neck between courses as narrower than the bead itself.

In practice

"It's PLA, PLA is stiff" describes the filament. The part is PLA in one direction and a stack of PLA-to-PLA welds in the other.

Not to be confused with

How this term connects

3D printingAnisotropyFDMInfillLayer heightPrototypeShellSLASLSSupport structurePrint anisotropy
Related Confused with