Cutting Wood, Stone and Bone

Wood, bamboo, bone, stone have grain patterns (cellular fiber matrix) that vary from linear to spiral. Spiral patterns are harder to split linearly lengthwise, and are usually cut with a saw.

Eg. Wood/Stone/Bone cutting: splitting vs sawing

A plank is split following the grain orientation, producing some splints/splinters, and then often smoothly planed;

while a board is sawn in any orientation, producing some powdery sawdust, and then often smoothly sanded.

word derivatives: 2D fiber -> 3D fabric | 2D mat -> 3D matrix

I intended to write a bit more, but it's rather technical.