Gokool, V.A.; John, J.A. and Koertner, A.J. (2018). Variability of Class Characteristics Observed in Die Cut Outsoles Composed of Both Rubber and Textile Materials. Journal of Forensic Identification, 68(2), 187-206.

This study examines the variability of certain manufactured features of unworn footwear outsoles that relate to their textile coverings. The manufacturing process that is used in producing the Sanuk Vagabond and Toms Classic involves die-cutting a sheet stock, which is composed of a mixed ethylene vinyl acetate and rubber compound with a textile layer faceted on top. The addition of the textile layer during the molding process reduces the amount of exposed mixed-rubber material to a dotted pattern of exposed area, thus creating a new feature that is variable to the class characteristics on the outsole. This manufacturing process introduces variance in outsole features from shoe to shoe. Measurements of the variabilities yielded statistical data that support the use of textile-induced outsole features in relation to outsole-imbedded features as an additional highly discriminating characteristic to be considered in footwear comparison examinations.