Linen rivals wool for longevity; its usage dates back almost as long, though in different regions and for different purposes. Where wool seems to have been first used in the colder climes of northern Europe, linen seems to have appeared first somewhere in the Middle East. In mythology it often represents purity.
Undoubtedly linen was the first vegetable fibre that was grown for the purpose of spinning and weaving, predating cotton. The flax plant from which it comes, linum usitatissimum, lends itself well to being grown in arid places, and archaeological evidence proves that ancient peoples knew it: hieroglyphs in Egypt have been discovered depicting the spinning and weaving of linen as everyday activities. The fabric became a luxury, used and worn in noble households. The burial cloths wound around bodies to be mummified were also woven of linen.
By no means limited to cultivation in deserts, flax has been grown with varying degrees of success in the Americas, India, China, Russia, North Africa, and much of western Europe, including Italy north into the Low Countries, Scandinavia, and England; but it had the greatest impact on the economy of Ireland, where it is still a major export product.
Linen likely appeared in Ireland in early Christian times; it is rumoured that St. Patrick is buried in a linen shroud, which if true would help provide a firm date of its arrival. Unfortunately we must instead rely on supposition and on the fact that by the Middle Ages the linen production industry was firmly established and employed many people for all stages of production, from growing the flax to marketing the finished cloth.
The British crown approved of linen in Ireland because it didn't interfere with England's wool-growing industry. The industry was originally quite haphazard; it became organised in the seventeenth century under the guiding influences of the Earl of Strafford and the Duke of Ormonde, who introduced regulations for quality control. By the eighteenth century, the heart of linen production in Ireland was in the "linen triangle" which extended from Dungannon east to Lisburn, then south to Armagh.
The industry received a boost when the Edict of Nantes was revoked in 1695, forcing many Huguenots to flee France, settling instead in Great Britain. One of them, Louis Crommelin, was raised and trained as a weaver of fine linen in his homeland; after he settled down to work in Lisburn, his weaving was so highly sought-after that he was appointed by the government to look into ways in which linen production methods might be improved. His work resulted in the creation of the Board of Trustees of the Linen Manufacturers of Ireland in 1711.
Irish linen became renowned for its fineness and remarkable quality. A damask tablecloth, dated to 1727, exemplifies the high standards that were in play in Ireland: it was woven in an intricate pattern, like many later cloths, but eighty years before the introduction of looms that could weave jacquard without labour-intensive and time-consuming work done by hand.
When the Industrial Revolution hit Ireland, automation of the linen industry was its main focus. The increased efficiency allowed for Irish linen to become even more prominent on the world stage, with more exports to more far-off places. Much of the Province's changing infrastructure evolved to meet the needs of linen producers. Irish linen also played a role in both of the World Wars of the twentieth century: sailcloth, aeroplane wings, ropes, canvas, and blackout sheets were all produced in the "linen triangle". It was not until after the Second World War that synthetic fibres developed sufficiently that they could replace linen in these capacities.
Linen is still produced all over the world, most notably in Ireland but also in Belgium and the United States. It comes from the stalk of the flax plant, linum usitatissimum, sown in April and harvested in August; because the fibres run the full length of the plant, for maximum staple length the plants are uprooted rather than cut, necessitating replanting each year. At their longest, fibres measure somewhere between 80 and 120 centimetres long; the longer the staple length, the greater the strength of the finished product.
The colour of the flax flowers, which bloom in early June, can sometimes be indicative of the quality of the fibres it will produce. The very best linens come from plants with violet-tinged blue flowers; colours range from this shade to an anaemic-looking pinkish white. In general, the lighter the colour is the weaker the flax fibres will be.
After a field of flax is uprooted, the plants are collected for rippling, a process by which seeds are removed for use in linseed oil or cattle cake for feedlots. Then the plants are returned to the field, where they are laid out for retting; here, the bark is allowed to rot, separating the fibres from the plant's main stem.
Scutching is the next step in processing; here, the fibres are beaten mechanically to separate the fibres for textiles from the woody stems of the flax plants (which are used in the manufacture of chipboard). Then, the fibres are hackled or combed to separate long line fibres from shorter ones, called tow; both are drafted into roving for spinning, but serve different purposes. Line fibres are dampened and wet spun into fine, crisp, and strong thread for machine weaving; tow fibres are dry spun into softer and heavier yarns, generally used for upholstery fabrics or sold to handknitters.
As a fibre for knitting or weaving with, linen behaves a bit like silk: it has no natural stretch whatsoever, giving it glorious drape, and often the finishing methods used by spinning mills make it lustrous. It has an extremely crisp hand, as though it has been starched even if it hasn't; unlike cotton or silk, however, it softens with age.
Also unlike cotton, the strength of linen increases by up to twenty percent when it is dampened; this means that linen garments and fabrics are very rarely ruined by washing. They do crease easily, but the creases steam out or can be pressed out by an iron on high heat.
Today, linen is most often used for bedding; table "linen" is a generic term which seems now to connote tablecloths and napkins made from synthetic fibres. It is also used sometimes for lightweight suiting fabrics and summer clothes, but almost always blended with cotton, polyester, or both, for softness and ease in laundering.
Sources:
Webb, W.H. History of Linen. http://www.pagelinx.com/ulsterlinen/2.htm
History of Linen. http://www.fergusonsirishlinen.com/aboutlinen/index.asp?itemID=2
How Linen is Made. http://www.fergusonsirishlinen.com/aboutlinen/index.asp?itemID=1
Interesting Facts. http://www.fergusonsirishlinen.com/interestingfacts/index.asp
"Prosperity, Revolution, and Famine: The growth of the linen industry up to 1770". BBC. http://www.bbc.co.uk/history/timelines/ni/growth_linen.shtml
The History of Flax and Linen in County Longford 1698-1998. http://www.longfordroots.com/history/h4.html