What is Cardboard?
[[File:Cardboard Main Flutes.jpg|thumb|250px|Pieces of corrugated cardboard.]] '''Cardboard''' is a [[wikt:heavy|heavy]] type of [[paper]], notable for its stiffness and [[durability]]. It was first invented in [[China]] some time in the 15th century, and is used for a wide variety of purposes. One of its more common uses is as a packaging material. Cardboard boxes were first produced commercially in 1817 in [[England]]. Corrugated (also called pleated) paper was [[patent]]ed in England in 1856, used as a liner for tall hats, but corrugated cardboard would not be patented and used as a shipping material until 20 December 1871. The patent was issued to [[Albert Jones]] of [[New York City]], New York for single-sided corrugated cardboard. Jones used the corrugated cardboard for wrapping bottles and [[glass]] [[lantern]] chimneys. The first machine for producing large quantities of corrugated cardboard was built in 1874 by G. Smyth, and in the same year Oliver Long improved upon Jones' design by inventing corrugated cardboard with liner sheets on both sides. This was now cardboard as we know it today. American [[Robert Gair]] was a [[Brooklyn]] printer and paper-bag maker during the 1870s, and while he was printing an order of seed bags a metal ruler normally used to crease bags shifted in position and cut the bag. Gair discovered that by cutting and creasing cardboard in one operation he could make prefabricated cartons. Extending this to corrugated cardboard was a straightforward development when the material became available. By the start of the 20th century, corrugated cardboard boxes began replacing the custom-made wooden crates and boxes previously used for trade. The [[John Harvey Kellogg|Kellogg]] brothers first used cardboard cartons to hold their flaked corn cereal, and later when they began marketing it to the general public a heat-sealed waxed bag of ''Waxtite'' was wrapped around the outside of the box and printed with their brand name. This marked the origin of the cereal box, though in modern times