Wool - Nature's masterpieces. An extremely attractive fiber for centuries.
Wool has the very special characteristics that it insulates against both heat and cold, which makes it extremely popular all over the world. It is its natural curly fibers that give this unique feature. The wool curls allows the yarn to get tiny air pockets. A wool sweater contains approx. 80% air, and an air layer is formed around the body, which in use isolates and holds the natural body temperature. The wool fibers contains so much air, it pulls moisture to itself and feels warm and comfortable even when wet. Wool fibers have very high elasticity and gives form stable sweaters. Wool has been used to knit sweaters for several generations and there has happened a lot in the development until today. Here writes "The great Danish" more information about the wool composition and characteristics. From Gyldendals open Encyclopedia.
There are many breeds of sheep and therefore many wool qualities. Wool quality complies mostly on wool fiber thickness. The thinnest under fur is the finest, but also the shortest. Long wool is rough. The quality you should first look for is thickness and then lengthwise. Short wool fiber/hair can be torn and a bit rough, which of course makes the wool less valuable. Within the same quality range are long underfur better than short.
Wool is water absorbent, thus it can absorb up to 40% water without feeling damp, on the contrary, it may feel warmer when wet. Other raw fabrics have this property in less degree.
All the way back to the shepherds of time, people have preferred the wool as the best protection against the cold. Shepherds used the wool to clothing and slept under wool blankets at night, and although the shepherds were staying out there year-round in all types of weather and spent the night in primitive huts, did they manage very well themselves outdoors, thanks to wool's amazing insulating properties.
In our modern times, the wool has for some time been repressed for many different synthetic fabrics, but more and more people will back to use wool, a natural product with so many benefits. You can find more relevant knowledge and information about the wool / wool on Woolmark.com