Sheep races and their development in different environments. The properties of wool and its treatments from fibre to felt and yarns. Woollen and Worsted and the practical significance of these terms. Completed 1977. Revised 1980.
The numbers in square brackets indicate where the photos from Karen’s original lecture should go. We hope to add these photos to this post at the soonest available opportunity.
Sheep  were among the first animals to be domesticated. Primitive sheepskins were hairy, probably like a deer’s coat in summer, but in winter the sheep would have grown an undercoat of fine wool, as fine and soft as fine wool today. The main ancestors of domestic sheep are thought to be the URIAL  from South West Asia, the MOUFLON of Europe and the ARGALI of Asia.
Ewes  of the urial type of wild sheep had small horns. The urial and mouflon rams both had curved horns while the mouflon ewe was hornless. They may be seen in representations from URUK and other places from about 3,000 B.C.
The argali  of Asia has massive spiral horns like the argali seen in Egyptian frescos. A sculpture at the British Museum shows it as sacred to the Egyptian god AMON .
A relative of the argali is the Big Horn of North America, whose ancestors are thought to have crossed to Alaska before the Bering Straits separated the continents.
Archaeological remains  of domestic sheep were first found in the Swiss neolithic lake dwellings and were described by L. RUTIMEYER in 1861. Since then remains have been found in many other places, and experts on sheep are studying the development towards our present day sheep races by paying special attention to the horns and their formation .
Dr. M.L. RYDER, author of “Sheep and Man”, has been studying the follicles  in which the wool fibres grow and how these are arranged in the skin.
In wild sheep the secondary follicles which produce the fine undercoat lie between the primaries, which produce the outer hairy coat. In modern sheep the secondaries lie on one side of the primaries. By studying the stages in between on old skins and parchments , more is becoming known about the ancestry of our present day sheep races.
Establishing and studying blood types may also be useful, but research work of any kind takes a long time and can be very expensive.
So we may not yet know exactly how sheep were bred and crossbred in ancient times, but what we do know is that some changes came about through selective breeding and others through changes in the environment.
Soil, type of feeding and climate could have an effect on both the wool and on the animal itself.
Fat-tailed sheep  provide an example of a natural modification accentuated by the breeders. The tail provides the fat reserves  without which the animal could not exist in the desert regions where it lives, but it is now so big that it sometimes trails on the ground and gets damaged by rubbing. To protect them the shepherds make little carts to tie to the sheep. Herodotus wrote about those little carts in the 5th Century B.C. and they are still being used.
There is another strange-looking sheep, whose progress we can follow from Sumeria  over Egypt to Abyssinia and West Africa.
This race does not appear to have changed much, so perhaps the conditions under which its members lived were alike. The first representation known was done about 2,000 B.C. by the Sumerians who lived in Mesopotamia . Another one, about 1,000 years later, was also found in Mesopotamia but in Assyrian times . This sheep was known in Egypt too at about the same time and appears still to be found in Abyssinia  and West Africa.
From the Bible we know that Jacob practised selective breeding. When he was promised all the spotted sheep  in his father-in-law’s herd, he increased his wealth by letting his own spotted rams mate with the biggest and strongest ewes of Laban’s herd. This would happen when the sheep met at the watering places.
Joseph’s  coat of many colours may have been woven from a natural coloured wool from spotted sheep .
The fleeces of primitive sheep, before it was much improved by selective breeding, would have resembled that of the SOAY  sheep, which till recent times have lived in comparative isolation on the St. Kilda island north of Scotland. The Soay is said to so closely resemble the Prehistoric sheep of urial breeds that they have been described as living fossils. The rams  have strong down-curved horns, while the ewes are often hornless, like their mouflon ancestors.
The fleece is usually a deep chocolate brown colour with a lighter patch  on the rump and underbelly. Some are much lighter and a few are jet black. Undyed yarns in these colours were used before Roman times for patterned textiles. Then as now these wools tended to fade. Some of the soay fleeces are of medium fine wool, with only a few hairs and kemps, which are undyeable, very hard hairs. Other fleeces are more primitive, with a hairy outer layer, many kemps and a softer woolen undercoat. The soay sheep moults in the summer and the fleece either falls off or is plucked off after being loosened by the onset of moulting.
The Spanish merino sheep
One of the earliest of the modern breeds is the MERINO of Spain, whose origins have given rise to a number of legends.
The history of sheep in Spain dates back to the earliest civilisations there. Sheep were brought to Spain by the Greek occupiers and the Phonecian traders. These sheep may have looked like those seen in a bronze figure from Crete, made between 1,300 and 800 B.C., of shepherds  carrying sheep, or in another figure of a ram  from Syracuse in 700 B.C.
Sheep from Asia Minor were thought to have inspired the story of Jason and the Golden Fleece, because of references to yellow sheep in other contexts.
Strangely, in Egypt a mummified sheep  was found which had yellow dyed bandages, suggesting a golden fleece and quite recently yellow sheep have been found among Australian merinos, which would appear to make the colour genetically possible. Another explanation of Jason’s fleece might of course be that fleeces were used to trap river gold!
There is also a legend which claims the name Merino to stem from a Roman officer of the occupying forces, MARINAS, who brought with him a flock of sheep from the TARANTO  region of Italy.
When the Moors arrived in Spain they are said to have improved the breed by crossing with other fine wooled sheep from North Africa. The Moors were excellent stock-breeders, and it is doubtful whether the Merino ever made more progress than while in their hands.
When the Moors left Spain there were two main groups of sheep. The TRANSHUMANTES or migratory sheep and the ESTANTES or stationary sheep. A Fresco from St. ISIDOR about 1,150 shows a Spanish shepherd  possibly guarding migratory sheep.
The traveling of the migratory sheep was controlled from the 14th Century by a committee of noblemen, clergy, and court officials, known as the Mesta. The Mesta jealously guarded the rights of the owners and caused laws to be passed for the protection of the wool industry. The penalty for exporting even a single sheep was death.
It was believed that the migration through the changing climates would improve the quality of the wool; and it might have kept the size of the sheep and the fibrelength of the wool even, because breeding for a larger size or a longer fibre length might have made the sheep less likely to survive the long travels; also the manufacturing of woolen goods was geared to the 2 inch staple and this probably made the breeders concentrate on producing finer and still finer fibres.
Several different breeds evolved through selective breeding, but fineness and evenness of fibres characterise all Merino breeds.
Sheep in Britain
In Britain the red mouflon is assumed to have arrived with the Celtic tribes who invaded Britain in the 6th or 7th centuries B.C. However, woolen fabrics were in use before the Celts arrived – a fact demonstrated by finds at Rylston in Yorkshire  and other places.
A piece of Bronze Age woolen cloth with a check design suggests a fairly sophisticated knowledge of techniques, incorporating spinning, weaving and possibly dyeing.
According to PLINY, when the Romans arrived here in 55 B.C. they found a thriving wool industry based on British sheep, with woolen cloth said to be “so fine, it was comparable to a spiders’ web”.
The Phoenician traders  may have brought fine-wooled sheep to Britain long before the arrival of the Romans, but the Romans are said to have brought white sheep, as they had to other occupied countries. Mostly these were longwools and it is believed that the Lincoln and Cotswold sheep are descended from the Roman sheep. Their fleeces still possess the main characteristics of being long, wavy and lustrous, but in Roman times they would have had a fine-wooled undercoat which has now been bred out.
The Romans encouraged the textile industry and established manufacturing centres, including – it is believed – at Winchester. In the 5th century the Saxon invasion nearly destroyed this industry – at least the luxury end. The Anglo-Saxons, so we have been told, only made rough coarse fabrics suitable for poor people.
The Normans, in their turn, greatly increased sheep-breeding. By the 12th century manufacturing centres were established at Bristol and Exeter and in Scotland at the mouth of the Tweed, though most of the trade was in raw wool, right up to the 14th century.
From the end of the Black Death in 1349 Britain became the greatest wool growing and manufacturing country in Europe and wool the mainstay of Britain’s economy.
This trade was from the beginning protected by a number of laws. Infringement of these laws were tried by a judge, sitting on a woolsack .
To this day the Lord Chancellor sits on a woolsack in the House of Lords – a woolsack  stuffed with wool given by Australian, New Zealand and South African growers.
Stock breeders continually worked to improve the quality of the wool. To suit the market one of the aims was to produce sheep with only one type of wool, in order to make processing into yarns quicker and easier. The Ryeland and the Lonk sheep are thought to have had medium length fibres of an even length by the 12th century.
We may not know yet how early the quality of the long-wools had changed to possess only the long wavy outer hairs, but we know that they have been highly thought of from both pictorial and other records of the Middle Ages, stating that travelers marveled  at the large and fine flocks of sheep to be seen on the Chilterns, the Dorset heights, the Cotswolds and the Lincoln and Norfolk Ridges.
Combed and worsted spun yarns from long-wooled sheep were much valued for embroidery wools from a very early age, because of their strength, smoothness and lustrous appearance. They became known as CREWEL Wools. Similar wools were used to embroider the Bayeux Tapestry and to weave the early tapestries. Their lustre has sometimes been taken for the lustre of silk.
At the end of the Middle Ages, there were already 44 different breeds of sheep in Britain. Up to the Reformation most of the wool was grown by the great monasteries, afterwards by the great landowners and their tenants. Under Elizabeth the First 80% of Britain’s export consisted of woolen goods, both in the form of raw wool and as manufactured goods.
Many laws were passed to protect this trade by Elizabeth I and succeeding monarchs right up to Charles II, who decreed that burial shrouds  should be made from wool. Most of these laws were vigorously enforced. Tapestries woven in Britain had by law to be woven on woolen warps. The penalty  for disobeying was hanging – with a woolen cord. Competition from abroad was strong. Many countries produced wool, but the greatest rival to British sheep was the Spanish Merino with its very fine wool of equal fibre length.
The development of the Merino
The MESTA continued to enforce the ban on export of sheep for a very long time, so apart from those sent to the Spanish colonies, none were known to have been exported till 1723, when a small flock was brought to Sweden by JONAS ALSTROMER on behalf of the Swedish Crown.
After this the Merinos were also imported into other countries: from Saxony  in 1765 and from there to Silesia. These sheep had been chosen from the very finest fibred Spanish types and led to the breed that produced the type of embroidery wool which we call BERLIN wool. Saxony Merino blood went into the development of Australian breeds, and so did the type of Merino which had been introduced into France by Louis XV.
These sheep, however, had been selected from the larger MUTTON type sheep, which were wanted in France for food, and as they continued to be bred for mutton, their wool became coarser.
In 1797 the first Merino arrived in Australia , brought there by two naval officers from the Cape of Good Hope: Captain John Macarthur and the Rev. Samuel Marsden, the founders of the Australian wool industry. Australian sheep were later crossed with American sheep , bred from earlier English mutton types and Spanish Merinos imported into the Southern States of America from 1798. By 1804 the Merino had also been established in South Africa.
The Industrial Revolution, which had begun to speed up in the second half of the 18th Century caused many upheavals, not least in the production of sheep. The increasing industrial population needed to be fed, especially as they were now earning the money to pay for their food. The factories also needed much greater quantities of wool to keep up their expanding production.
Most sheep can provide both wool and mutton, but not equally well, and the British sheep industry was at first uncertain which market they should satisfy. Other sheep farmers increased their efforts to produce finer wools. They were encouraged by George III, Farmer George, who was given a flock of Merino sheep by Spain in 1787. But in spite of royal and aristocratic patronage attempting to build up such an industry in Britain, it was now doomed to failure.
Captain Macarthur put it like this on a visit to Britain:
Captain Macarthur considers it his duty respectfully to represent to his Majesty’s Ministers that he has found from an experience of many years, the climate of New South Wales is peculiarly adapted to the increase of fine wooled sheep, and that from the unlimited extent of luxuriant pastures with which that country abounds, millions of these valuable animals may be raised in a few years, with but little other expense than the hire of a few shepherds.
Captain Macarthur was right and the field lay open from now on for Robert Bakewell and his disciples to breed English sheep mainly for mutton with wool a useful and sometimes valuable by-product, but never again for the fineness of the fleece.
Much has been published about the history of sheep and the production of wool by the International Wool Secretariat and the Textile Institute in Manchester.
We shall now look at the wool fibres themselves, and how their chemistry and construction affects the properties of woolen goods.
The structure and properties of wool and hair from different animals may vary in degree but not in kind. They are similar in many ways.
A wool fibre seen through a microscope  has 4 distinct regions:
- The outer sheath or EPICUTICLE: which is a thin water-repellant membrane and the only non-protein part of the fibres, which it protects as a covering of wax. This membrane would repel the water of a short shower of rain, but it has microscopic pores through which water vapour may penetrate into the fibre. Wool fibres can absorb up to one third of their own weight in water vapour without feeling damp. This construction will release the vapour again, but only slowly so as not to chill the body underneath, whether that be the animal or man in sheep’s clothing.
- The Scale Cell layer or CUTICLE: beneath the wax covering is a layer of flat scale-like cells, which overlaps on the fine underwool like shingles on a roof, and are placed edge to edge on the outer hair, thereby providing the sheep with a smoother, more water-repellant outer covering and us with the strong and lustrous yarns that are so suitable for tapestries, carpets and embroidery.
- The CORTEX, which forms the bulk of the fibre, consists of millions of long spindle-shaped cells which provide strength and elasticity. In the wool fibre protein molecules lying alongside one another are held together at intervals by chemical crosslinks – polypeptide links – when the fibre is stretched, the chains unfold; then when the stretching force is removed, they return to their folded state.
- The MEDULLA: which is found in many wool fibres, mainly the coarser ones, runs lengthways through the centre. This space may be empty, or it may contain a network of cell walls. The Medulla accounts for up to 90% of the volume of a KEMP fibre. The Medulla is either absent or invisible in Merino fibres.
Wool is Protein. KERATIN, the substance of wool, is similar in its essential properties to the other proteins from which the animal body is built, which includes feathers, hair and horn. KERATIN contains the elements carbon, hydrogen, oxygen, nitrogen and sulphur.
A wool fibre grows from a follicle  and, like any other hair, it is dead above skin level. Wool cannot change its physical form once it has left the follicle. If the tiny rod of Keratin is damaged or severed by illness, it remains damaged or severed.
It is often not possible to spin the wool of a sheep that has suffered either illness or starvation.
Wool fibres are unique in their wavy structure  or crimp, which enable the fibres to hold together when twisted into a yarn. This three-dimensional waviness, which is greater in fine wools, echoes its complex molecular structure of polypeptide chains.
The effect of WATER on wool is a very important factor both in the production and the later care of woolen goods.
Wool prefers a moisture content of about 17%, but can absorb up to one third of its own weight. In dry countries, when the water content drops, the wool becomes thin, dull and lifeless and will eventually disintegrate. The action of water on wool is complicated by the chemical crosslinking which holds wool molecules together. The relatively small molecules of water are able to penetrate between the longer wool molecules and to prise them apart. This weakens their hold on one another; however, the chemical bonds prevent damage from occurring, so all is well, providing the water is not either too cold or too hot. Hot water causes most damage. The wool loses its strength when heated in water under pressure. At 120°C it will dissolve.
Wool fibres become plastic in hot water, particularly in boiling water. If stretched out hot and allowed to cool under stretched conditions , it will stay that way and only return to its original state if heated above the previous temperature. This is like the principle of a permanent wave in hair and the reason why we can set creases in trousers and pleated skirts.
Wool decomposes and turns yellow at 130°C, and it chars at 300°C with a smell like burning feathers. Wool does not continue to burn when it is removed from flames. Each fibre forms a charred black knob. This fact is sometimes used to identify wool by burning tests.
Woollen materials decompose under the action of sunlight. This process begins even before the wool is removed from the sheep. The sulphur in the wool accelerates the process which starts with the fibres becoming discoloured and developing a harsh feel. They lose strength and the dyeing properties are affected. The wool on sheep, much subjected to sunlight is also particularly sensitive to alkalis.
Proteins are easily degraded and attacked by a number of chemicals and have less resistance to environmental pollution than cellulose has. When wool is stored in the right conditions, however, it shows little deterioration, even at a very great age.
The wool composition itself includes the SUINT, salts from perspiration and wool grease. Raw wool contains 20% or more wool grease, which is Lanolin.
Before we go on to carding and spinning, we need to sum up the first part of this talk.
Primitive sheep had two very different kinds of wool: Long, smooth and lustrous outer hair and short, soft and crimpy under wool. To get the best out of each type they had to be separated for spinning, and this took time and so cost money.
Selective breeding and crossbreeding aimed at providing sheep with only one kind of wool  to produce either long, hardwearing worsted-yarns or soft, warm woollen yarns.
This has resulted in about 200 different breeds with four distinct types of wool.
- Woolhair only: Soft crimpy 5-15 cm. long. Woolhair is used for high quality clothing, and is grown on sheep, bred from the Merino and English Down races.
- Outer Hair only; Smooth, shiny, slightly wavy about 40 cm. long. This makes WORSTED yarns used for carpets and furnishing, and is produced by breeds like the Lincoln, Leicester, Romney Marsh and Cheviot.
- Crossbred Wool : A mixture of the qualities of the Merino and English Longwool sheep. It is 15-20 cm. long, harder and less crimpy than the merino and used extensively for clothing.
- “Primitive Wool”; This term may be used for wool from sheep which still have 2 layers of wool . Among them are the Greenland sheep, the Norwegian Spelsau, the Swedish Landrace, Gotland Sheep, Danish Marsh and Dune sheep, English Mountain sheep, Scottish Blackface, Hungarian Goggel, Austrian Zakel  and most Asiatic sheep, like the fat-tailed Karakul  from which we also get Persian Lamb Coats. Icelandic sheep produce wool with a large empty medulla and is light, airy and quick drying. Perhaps it was the breed of sheep in any particular region which first determined the basic characteristic of fabric woven in that region .
The outer hair on some of these “primitive” sheep can be more than 50 cm. long and are very smooth and shiny. They are used for special purposes which include Rugs, Embroideries and Tapestries because of their strength and hardwearing qualities as well as for their lustrous beauty. Really primitive sheep like the Soay, the Shetland and the sheep of the Faroe Isles and Iceland still moult in the early summer. Plucking, which can be done at the onset of moulting, before the fleece falls off by itself, allows for attempts to reject the coarse hairy fibres, which are often loosened later than the wool. Plucked or moulted wool has a naturally finished tip to the end of each fibre, which makes it easier to spin.
Sheep lost their ability to moult in the process of becoming domesticated and advanced. They probably could not easily survive now under their heavy coat , if they were not cut or sheared because fleece can weigh as much as 15 kg. (about 2 stone). Shears have been known for 3,000 years, but have only been in general use for sheep shearing since the 13th century . Shears consist of two blades hinged with a simple spring and have not changed their basic shape since they were first invented.
The best length for the cutting edge of the shears is about 15 cm . so while it is difficult to recognise ancient sheep-shears by their shape alone, it is fairly certain that shears with blades much longer or shorter than 15 cm. are not for clipping sheep.
Their shape  makes it possible to remove the fleece in one piece , which is an advantage in the later manufacture of wools – but though shearing is now done with electric clippers , the drawback is that it still needs highly skilled manpower and there is always the possibility of damage to the sheep. Recent knowledge, gained through archaeology and medical science relates to the links between illness and bone-structure deficiencies. As a result experiments have succeeded with drugs being administered to sheep, which cause a reaction similar to moulting, but better, because the fleece can be removed in one piece after a few days. The wool would have natural tips at both ends, just like moulted or plucked wool, and therefore be easier to spin.
The first cutting of medium to fine wooled sheep is used for making garments to be worn next to the skin as the fibres with one natural tip makes for fewer cut ends to irritate sensitive skins. The best wool is grown during the first six years of a sheep’s life.
In cold damp climates, winter wool will be coarser than summer wool which is longer, shinier, cleaner and more shrink-proof.
Wool from slaughtered sheep is not as good as wool from live sheep.
Wool which has been cut from sheep which have died from natural causes is of a very poor standard.
Wools damaged by illness or spells of bad nutrition cannot produce quality yarns, it breaks easily in the part grown during the time of illness or starvation.
Before spinning, the wool is sorted by separating the different areas . Wool from the shoulders and sides are best, because it has had less exposure to the sun than the fleece on the back of the sheep, although this actually has the longest fibres. Wool from the belly is the softest and from the legs the poorest.
Sheep have warm coats to protect their best wool from the sun in various places throughout the world.
Dirty wool , damaged by urine is removed together with foreign matter , twigs, leaves, etc.
Wool is usually washed  before spinning, sometimes by washing the sheep, sometimes by washing the sorted fleece. Washing the sheep is good, provided it is done properly but if the process of making soap is started and insufficient water is used, this can cause a great deal of damage, since the fleece must be well rinsed afterwards.
The reaction in itself is very useful when properly understood;
One might call it the sheep’s own soap factory . What happens is that when the perspiration of the sheep, which contains Potassium salts mixes with water and the ammonia from the startled squirt of urine, when the sheep is driven into the water – LYE is produced which in turn combines with the woolgrease to make soap. This soap dissolves more of the wool – grease which can then be rinsed away – up to 80% can be removed this way.
This was mostly how sheep and woolwashing was done in the past. Now fleeces are scoured  in the factories and all of the natural grease is removed  before spinning to be replaced afterwards with mineral oils.
The invention of spinning must have been made in many places, and was probably first thought of in relation to whatever materials were available in any one region.
In the case of wool, it cannot be known which came first, spinning and weaving of wool cloth or felting. Both methods could have stemmed from observation of the natural matting of the coat of primitive sheep.
Felt forms naturally in the fleece of moulting sheep by the rubbing of the animal, so it is unlikely that the legend of St. Clement , the patron Saint of Hatters, has any foundation. He is said to have discovered felt, when he put fleece in his sandals on a journey and later found that pressure, moisture and friction had matted it together.
It is most likely that felt originated in Central Asia . The nomadic peoples of Mongolia and Turkey still make and use felt for their tents.
Dr. Ryder  has observed that because of further rubbing of the felted masses, mouflon staples twisted themselves into long strands, nearly ready for weaving. Twisting is the operative word. Twisting adds strength to strands of fibres.
Observation of this fact probably provided the inspiration to imitate the action, first perhaps by rubbing the fibres between the hands or with the palms on the thigh  as in ancient Greece or Egypt and later also in some North American Tribes. This method means that the fibres are arranged first and then twisted; later the more efficient way of drafting the fibres against the twist by using a spindle became the norm. This method is demonstrated by Egyptian women pictured at Thebes.
Early wool was spun straight from the fleece with very little preparation, so that the yarn contained the long hard outer hairs, the short soft inner wool and a very high proportion of highly prickly and hard kemps as may be seen in some Bronze Age cloths.
To get a uniform yarn of even texture it must soon have become apparent that it would be necessary to spin the inner wool and the outer wool separately and differently. Into woollen and worsted yarns.
Woollen Fibres are prepared for spinning by being teased and carded into fluffy rolls, with the fibres arranged to spiral round each other from end to end of the roll which is called a ROLAG .
Carders made from boards with teazles  fixed in rows were the first to be used. The metalwire carders became usual in the 13th century . When the rolags are spun they will pull out evenly but twist into each other sideways to make a round elastic bulky yarn, capable of trapping air to make the yarn warm and comfortable when made into clothing. The fibre ends which stick out because of the spiral  arrangement of the rolags will trap more air; they also break the light reflection from the yarn surface, so that the colour in woollen yarns will be seen as soft and matt.
Woollen yarns are used for clothing and bedding because of their warmth and elasticity, but they do not take hard wear, and articles made from woollen yarns should rest in order to relax the fibres between each use.
Worsted fibres are combed  to be exactly parallel and straight so that they can be spun in this straight position.
This makes a solid yarn, with no room for trapped air. It is cool, hard and very resistant to wear. The lack of air pockets and the straightness of the fibres is the reason for the possibility of heat-setting pleats and creases. The longer and smoother the original fibres, the stronger and more lustrous the yarn.
Light reflection is greater from materials with few breaks on the surface and greater light reflection makes colours appear clearer and more precise. These qualities make worsted yarns suitable for fabrics requiring strength, well defined design and a smooth, shiny, dirt-repellant surface.
It is used for outer clothing and for furnishings of all kinds from upholstery, carpets and curtains to tapestries, and for crewel work embroidery.
Woolcombing appears to have been done very early, Bishop Maize, the Patron Saint of Woolcombers  is said to have been tortured to death with woolcombs in A.D. 316, so they were well established by this date – possibly introduced by the Romans .
Crossbred Fibres can be spun both as worsted and as woollen yarn. The choice will be according to the ultimate use which will be made of the yarn. Both old and modern spinning techniques can be modified to produce yarns which has strength and warmth combined.
From very early times people found ways of spinning yarns to suit their purpose. Warp yarns used for tapestries continued to be made with a descending spindle, according to the principle of worsted spinning because this process could efficiently eliminate air, lessen the water absorption and help to keep the fabric stable, thereby increasing its resistance to mechanical wear.
Spinning warp yarns with a descending spindle  lasted in Norway till recent times, because of the extra strong warps needed for the upright looms in use there. The early spinning wheel introduced in the 13th century could not at first do worsted type spinning.
Twining or plying  can be used both to strengthen a yarn and to accentuate characteristics. A yarn plied from two threads has a livelier surface than one consisting of only one thread. This is because light is reflected differently when two yarns are twisted round each other. Three threads plied together makes a round yarn with less surface for the light to play on. A three-ply yarn is suitable for ropes and for warp yarns in tapestries because of its strength and smoothness.
Weft yarns for tapestries need the life and play with light of two-ply worsted yarn.
The amount of twists in the spinning make a lot of difference to the finished product because yarn is stronger according to the number of twists.
Softly spun yard tend to felt and shrink when washed, differences also depend on the direction of spin, which in wool may be either way. Right or left. The two directions can be distinguished from each other, being referred to as S and Z , to correspond with the slope of the twists. S is for a left twist – Z for a right twist.
Plying can be done in the same direction or against. When it is done in the same direction, the yarn will be harder, less elastic and tend to twist and curl up. When it is done in the opposite direction, it will be warmer and softer, with an increased play of light.
The different directions in spinning can be used for effects . The Chinese knew this when they made crepe fabrics by alternating S and Z spun threads both in the warp and the weft.
[unreadable] fabrics with a check design obtained in a similar manner are also known.
Many fabrics woven on simple looms have taken on a completely different aspect in this faction. For handweaving it used to be the rule that warp threads were S spun and weft threads Z spun. If this rule is followed the cloth will be easier to full and tease, softer and more comfortable to wear for clothing.
S stands for:
Traditional worsted spinning
Stronger, harder, cooler yarns
Z stands for:
Traditional woolen spinning
Weaker, bulkier, warmer yarns
Worsted type fabrics are set by passing and [unreadable]
Woolen type fabrics can be fulled, teasled and sheared.
A description of woven fabric should include:
Type of weave
Type of yarn
No of yarns in 10cms. Warp and weft.