Brain used variety as the basic unit of description, comparison and interpretation.
An example of a drawn bead variety from Brain is IIA1, which is a simple bead with rounded ends and white color; the color in this case draws the "1" variety.
First, a basic description of the Kidd and Kidd bead classification system follows.
The Kidd and Kidd system's first level of classification relied on the method of bead production, i.e. Tube beads were manufactured by drawing apart a hollow glob of molten glass.
Brain sized his IIA1 examples as very small to very large.