Even the most elaborate tri-radial spinnakers cannot perfectly mirror the actual stress paths in a working spinnaker. Consequently, the bias, or off-axis stability of the fabric, makes an important contribution to a smooth, fast shape. As a general rule, a firm, highly resinated finish will improve the stretch resistance of a spinnaker cloth, particularly on the bias. It also tends to lock the fibers together, thus decreasing tear strength. Conversely, a softer, more elastic finish does less for cloth stability, but allows the threads to shift a bit and resist tearing. Luckily, this tradeoff is not an absolute, and cloth manufacturers are getting better at combining low stretch and tear resistance. According to industry-standard 20- and 40-pound tests, Bainbridges premium 600N AIRX spinnaker cloth exhibits less than half the bias and fill elongation of the same manufacturers 0.5 oz. Stablekote material. Better yet, AIRX is 30-to 40-percent better in tear tests (impaled on a nail and loaded to failure). Both weigh in the normal range for half-ounce cloths.