When a box becomes wet, the performance of the box and its closure are reduced. It is desirable to have box closure methods that retain an ability to keep the box closed when wet. Sealing or reinforcing methods sometimes are useful to improve performance of wet boxes and closures. Water resistance is sometimes a regulatory or contractual requirement.

A test result indicating that a box closure tape or adhesive is soluble or dispersible in water is an indication that its function will be significantly impaired when wet. A test result that does not indicate solubility or dispersibility does not necessarily ensure that the bonding ability will be satisfactory when wet or that the performance of the box closure will be satisfactory when wet. Package performance testing described in the water resistance section of Practice D1974 is useful to further investigate the effects of water on package and closure functions.