Also called anti-scuff facing, it’s a protective polyurethane film. It can be applied to the edges or striking surface of the bat to help prevent cracking and splits. Some players use it as a substitute for going through the laborious process of knocking in a bat, though for maximum durability it should be applied after this has been done.The anti-scuff sheet can be moderately effective when used for a repair, if a bat has been poorly looked after and has started to split, but only at the amateur level. There’s no rule preventing its use in matches, though professionals tend not to. For them, a bat needs to be in perfect condition or they’ll change it.