Corrugated fiberboard, corrugated cardboard, or corrugate is a type of paper packaging material consisting of a fluted corrugated sheet and one or two flat linerboards. It is used for making corrugated boxes. Corrugated paper was patented in England in 1856, but corrugated boxboard for use in shipping material was not patented until 1871. Several properties and characteristics can be measured for corrugated board, including moisture content and burst strength. Corrugated board is manufactured on large high-precision machinery lines called corrugators. Packaging engineers design corrugated boxes to meet the particular needs of the product being shipped. Old corrugated containers (OCC) are an excellent source of fiber for recycling.