PCA of Still Bay bifacial points showing the first two axes of variation with raw-material type as a grouping factor.

<p>Convex Hulls of each group show that points made on different raw-materials overlap on the major axes of variation. Artefacts are plotted at the extremes of PC1 for illustration purposes. Additionally the red and blue outlines indicate the two-dimensional edge configurations of computed theoretical shape extremes on PC1. Point scan models are not to scale.