Hardboard is a cheap, thin sheet made from tiny pieces of wood — really wood fibres — pressed together until they become one hard board. People use it on the back of cupboards, under a floor, or for a simple indoor panel. It is not a plank of real timber, and it is not hardwood (oak, teak, and other strong trees). It is also not the same as MDF, the thicker, smoother board you see in a lot of furniture. Hardboard is usually thinner and has one shiny, smooth face. If it gets wet it can swell and lose its strength. You buy it in sheets at a hardware shop. The word is almost always a noun for the material; you might hear someone say they hardboarded a wall, but that use is uncommon.

硬質纖維板。五金行常只寫「纖維板」。不是密度板（MDF），也不是實木的 hardwood。