How beautiful will your carpet be after five years of foot traffic? Engineers created a test to assist in such projections. The Hexapod test is an international testing method that evaluates the ability of carpet to retain its appearance after being subjected to simulated foot traffic. The Hexapod test subjects carpet to a fixed number of impressions with an eight-pound ball. Afterward, the carpet's finished appearance is graded using the Carpet and Rug Institute's performance 1-to-5 scale in increments of 0.25. A low-performance carpet may have a 2.25 rating due to heavy matting while a high-performance carpet may have a 4.75 rating due to minimal crushing or twist deterioration. As a general rule, more expensive carpet will have a higher rating than a less expensive carpet. Furthermore, a heavier face weight will create a higher Hexapod rating (if all other factors are equal). The Hexapod test does not measure stain resistance.