Haircloth is a stiff, unsupple fabric typically made from horsehair and/or from the wooly hair of a camel. Although horsehair generally refers to the hair of a horse's mane or tail, haircloth itself is sometimes called horsehair. Horse or camel hair woven into haircloth may be fashioned into clothing or upholstery.

In the history of brewing, for drying the malt, haircloth was spread over the kiln floor to keep grain from dropping down into the furnace. Perforated metal or tile (gratings, meshes) were also used, but had a drawback of scorching the grain. (source)