Wet strength

The wet strength of paper and paperboard is a measure of how well the web of fibers holding the paper together can resist a force of rupture when the paper is wet. Wet strength is routinely expressed as the ratio of wet to dry tensile force at break.

With combined board such as corrugated fiberboard or with laminations, wet strength also includes the ability to stay intact under humid or wet conditions. Wet strength adhesives are often needed.