Variations in Wool

One of the joys of my recent wool research is getting to experience first-hand so many amazing varieties of wool.  Many of these come from sheep breeds purposely bred for different characteristics such has high fiber yield, staple length, crimp, etc.  Through careful research we can determine which breed will supply the best type of fiber for a given project (historical or modern), but we often over look the fact that wool can vary with environmental factors, age, gender and even within the coat of a single sheep.  (These notes specifically refer to Viking era or Norse projects, but many of the points could pertain to anyone working with fleece for a historical project.) 

When considering a whole fleece:

• Primitive sheep still often have dual coats.  Tog and Thel, as they are called in Icelandic sheep, were often used differently as the tog is longer, stronger and helps to shed water while the thel is short, soft and insulating. 
• You can, of course, spin both coats together, but this can sometimes result in a good deal of haloing caused by the variety of fiber lengths.  Haloing can result in an exceptionally sticky warp that makes weaving difficult.
• The finest, softest wool comes from the neck and sides of the animal, with the worst quality being located at the the belly and legs. (Ostergaard, 44) 
• Historically, you would have used fleeces from several sheep, and be able to select the best areas of those for certain items, such as those worn next to the skin, and use the coarse wool for things like outerwear, rugs or blankets.  As most of us are not sheep farmers, we do not typically have access to 3 or more fleeces at once to truly sort out the wool when we process it for our projects. 

Rooing vs. shearing:

• As I mentioned before in another article (located here), many of the primitive sheep breeds still shed their coats.  When wool sheds, the thel will shed before the tog, making the overall harvest less hairy than if shorn.  Shorn wool must be manually separated if one wants only the finest or strongest wool for a particular use.  (Ryder, Survey, 400)

• _Medieval Greenland finds support both shearing and rooing as processes used by the Norse.  (Ostergaard, 43)  Earlier finds show evidence of both cut and pulled locks as well.

Age and Gender:

• A lamb’s fleece is the finest, softest fleece.  Even the tog is exceptionally fine, however, it is not as easy to purchase enough lamb fleeces, in similar colors, to weave enough cloth for a garment. 
• Typically a ewe’s fleece is more fine than that of a ram.
  
• Fleece tends to get more coarse as an animal ages.
  
• You will get the most fleece from a 3-5 year old animal, but it will not be as fine as that from a younger animal.
• Fell wool (wool collected from a dead sheep, because nothing was left to waste in period) does not last as long, or wear as well, as that from a live sheep.  Often it was blended with other wool to be used.  (Ostergaard, 39) 

Environmental effects on wool:

• Many modern farmers shear twice a year and the summer fleece is different than a winter fleece (the summer fleece tends to have less chaff in it than a winter fleece).

        - Heterotype hairs of some sheep, such as Icelandic, will also change throughout the year.  The         fleece growing during the winter on an Icelandic sheep will have tog that is more soft and                 insulating while that growing over the summer will be more hairlike to shed water. (Ryder,         Survey, 400)

• Too much heat and moisture can actually felt a fleece.
• Nutrition plays a huge role in fleece development.

        - The mother's nutrition will permanently affect the fleece of her lambs (including how dense             the underwool will be).  Studies show that a lamb whose mother had poor nutrition and who             also had poor nutrition for the first few months after birth would produce 20% less wool as an         adult.  (Khan, 13763) 
        - Lambs born as twins produce less wool as adults than those that are singles. (Khan, 13763)

• Disease, stress, and parasites can affect the quality of the fleece (Khan, 13762)

        - Diseases like fleece rot and dermatitis can affect the strength and quality of the fiber.
        - Steely wool is cause by copper deficiency (loss of crimp, low tensile strength).  Copper                 deficiency can also cause loss of pigment in dark colored sheep. (Khan, 13764) Zinc deficiency         causes brittle wool, loss of crimp, and, when extreme, can cause the fleece to shed.

Coming soon:  Considerations When Choosing Wool for Your Historical Project


My other sheep articles:
http://awanderingelf.weebly.com/a-wandering-elfs-journey/category/sheep

Resources:

Dýrmundsson, Ólafur and Niznikowski, Roman.  “North European short-tailed breeds of sheep : a review,” 59th Annual Meeting of the European Association for Animal Production.  2008

Ekarius, Carol and Robson, Deborah. The Fleece & Fiber Sourcebook: More Than 200 Fibers, from Animal to Spun Yarn (Storey Publishing, LLC), 2011.

Khan, M. Jamshed. “Factors affecting wool quality and quantity in sheep”, African Journal of Biotechnology, Volume 11, 2012.

Ostergaard, Else. Woven into the Earth: Textile finds in Norse Greenland (Aarhus University Press), 2004.

Ryder, M. L. Sheep & Man (Gerald Duckworth & Co.), 1983.

Ryder, M.L.  “Survey of European primitive breeds of sheep”, Annales de génétique et de sélection animale, 1981.