A property of paper that refers to its ability to keep from slipping or sliding. (Friction is the force that resists one object's sliding over another.) There are two basic types of friction that need to be taken into account: static friction, which is the force that resists an object's beginning to slide from a stationary position, and kinetic friction, the force that resists a moving object's continued sliding. A paper's frictional resistance is primarily an issue in paper and paperboard manufactured for use in cartons and other packaging, in which excessive slippage during shipping and handling can result in damage to the contents of the packaging, or to the contents of other cartons or packages. Paperboard surfaces are often treated with antiskid treatments to help increase frictional resistance. Frictional resistance is rarely a concern in most printing applications. A greater degree of frictional resistance can prevent sheets from sliding over each other easily, which can either cause feeding problems in the press, or generate a buildup of static electric charges.