This test measures the amount of moisture in pulp, paper or paperboard “as received” (TAPPI T412) or after conditioning at TAPPI Laboratory Conditions (73°F and 50% RH per TAPPI T550). A representative sample of the material to be tested is placed in a sealed pre-weighed weighing tin and the initial sample weight is determined. The weighing tin is then opened in an oven environment of 105°C until the weight of the same no longer changes with time. The “dry” weight of the sample is measured and the % moisture of the original sample is calculated. Papermaking fibers naturally absorb moisture from the environment and the amount of moisture in paper or paperboard significantly affects strength and elastic properties. TAPPI Test Method T402, Standard conditioning and testing atmospheres for paper, board, pulp handsheets, and related products, provides conditions for preconditioning and conditioning of paper materials to help control moisture content prior to testing.