This standard practice defines the standard atmospheres for normal preconditioning, conditioning, and testing of paper and paper products, paperboard, fiberboard, and containers made from them. It also specifies procedures for handling these materials in order that they may reach equilibrium with the respective atmosphere.

This standard practice is also applicable to standard pulp test handsheets, except that the preconditioning procedure is omitted, that is, the sheets are not dried to conditions below those obtained by exposure to the standard conditioning and testing atmospheres. (See TAPPI T 205 "Forming Handsheets for Physical Tests of Pulp.")

This standard practice does not include special conditioning and testing atmospheres, such as those that attempt to simulate tropical or arctic environments.