Fig. 7
From: A Sui-Tang dynasty woman’s crown: analyzing form, glass and class

PCA is used in these potash-lime glass decorations to obtain statistical models that make significantly visible the samples’ chemical components and their proportional differences. (The 4 Categories—Dynasty, Place, Type and Color which were selected are the four parameters that are most likely to affect the potash-lime-glass glass composition. Dynasty and place are dependent on the samples’ sites, type is the archaeological type of the sample, color is the physical color of the glassware)