Results on the characterization of the tearing behavior of a series of uncoated and butyl rubber coated polyester plain weave fabrics are reported. Polyester fabrics were obtained from commercial source to cover a broad range of fill yarn properties. Dip coating was used to obtain coated fabrics. Data indicates that the tear behavior of this composite system can be analyzed in terms of initiation and arrest loads, stiffness, and number of yarns per peak. Results show that yarn mobility and subsequent del zone structure play a critical role in each of these characteristics.