History

• The first hardboardlike products were manufactured in the early 1900s by hot pressing paper fibers in steam. The process was refined by William H. Mason and in 1924 he invented hardboard and produced the first commercial version at his Masonite Corporation. The main ingredient in hardboard has always been wood fibers torn and ground between rotating disks into a pulp.
  
  

Wet Manufacturing Process

• There are two basic processes for the manufacture of hardboard: wet/wet and wet/dry. The wood fibers are pumped into a forming tray in a liquid form with water added. In wet/wet, the pulp is pumped into a drying screen and pressed from the top with a flat plate producing one smooth side, or S1S. In wet/dry, the pulp is partially dried before being pressed between two smooth plates to produce two smooth sides, or S2S.
  
  

Dry Manufacturing Process

• The dry process uses air to move the fibers into formers which then press it into sheets. All dry manufactured hardboard is S2S, or smooth on both sides. The dry process randomizes wood grain in three dimensions, making the product even stronger and more consistent in texture and density.
  
  

Unique Qualities

• Cellulose gives wood its strength; lignin is the natural binder that holds the fibers together. Hardboard is the only manufactured wood product to use lignin as opposed to a synthetic binder. The binding properties of the lignin in the wood pulp are reconstituted by a heating process to solidify the hardboard, making it one of the strongest and most stable of manufactured wood products.
  
  

Uses for Hardboard

• In addition to hardboard panels, hardboard is manufactured into a variety of construction products. One of the most common is perforated hardboard, also known as pegboard. The ¼-inch hardboard is bored in a grid pattern for attaching special tool pegs for hanging hand tools and other items. Hardboard can also be incorporated into veneered panels and covered with plastic laminates. Artists frequently use it in place of canvases, with a gesso primer coat. It is used in the manufacture of trim moldings, furniture, doors and even automobile door panels.