Wednesday, August 27, 2014

Wool and all the possibilities!

Guest blogger Beverly Kemp-Gatterson will be writing a series of post on textiles.  Thank you Beverly for sharing your knowledge of textiles with us!


What do we know about wool?

Emerald Green Wool
Plum Diamond Wool

Wool is a fiber that comes from the covering of sheep and it is as old as the Stone Age. There are about 40 different breeds of sheep that produce about 200 types of wool fibers of varying grades. The best quality wool comes from the back, sides, and shoulder; the poorest quality comes from the lower legs.

Think of wool as hair, which it is, and consider the thickness or fineness of the fiber. The thinner the fiber diameter, the better the properties (or grade) of the wool. Merino wool which comes from the Merino breed primarily in the U.S. is considered the best grade of wool. 

What are some favorable and unfavorable properties of wool?

As we know, wool is mainly composed of protein which is similar to human hair because it is an animal fiber. 


Favorable

Wool has:
a. Good resiliency- wrinkles come out if the garment is hung in a moist atmosphere
b. Good hand- it feels good on the body
c. Good drape and elasticity- it hangs well in garments and the fibers can stretch without being distorted and will spring back to its original shape
d. Very little problems with static electricity
e. Makes warm garments because it absorbs moisture vapor slowly without feeling damp on the body. And it provides a chemical reaction that releases energy in the form of heat. Wool fabrics also have an excellent insulation property because the fibers have a natural crimp, which prevents them from packing together. So what happens is trapped air space is formed and this becomes the insulating barrier. This property can keep us warm or keep us cool.


Unfavorable

Wool :
a. Loses strength when it is wet. 
b. It has poor luster
c. Most common method of care is to dry clean
d. Felting will occur in the presence of heat, moisture, and agitation which causes the fibers to interlock with each other
e. Is vulnerable to moths
f. Has problems with pilling (little balls of fibers that sit on the fabric surface)
g. Is usually more expensive because of the limited quantities available


FAQs

1. Wool is too heavy and I can only wear it in the winter. Why should I make a garment to wear in Houston’s hot, humid climate?
For the very same reasons mentioned above. If the wool fibers are fine, this fabric is commonly referred to as tropical weight wool. It has a soft, flowing, smooth hand with good drape. So, it is not heavy on the body. Remember, it absorbs body moisture and creates a dead air space between the person and the garment. So, the person will not feel warm. Actually, wearing a garment of tropical wool (whether a dress, slacks, or jacket) is cooler in the Houston heat than a garment made with polyester. The three wool fabrics from Sew Much Fabric are excellent examples of tropical weight wool. They are light, yet sturdy enough to hold the shape of the garment. Note that men’s suits are made from tropical weight wool. What that means is these fabrics can stand up to tailoring techniques and still retain their beauty and utility. And be cool!

2. What if I have fabric that I’m not sure if it’s wool or not. How can I determine what the fiber content is?  There are a couple of things you can do, although you can’t be absolutely sure if you think you have a blend of wool and some other fiber. Let’s look at these methods.

a. Burn Test- if you pull a yarn from your fabric and apply a flame to it (like a match or a candle), the yarn will burn, it will shrink from the flame, it will have a very strong odor of burning hair and the residue will be black and hollow and will crush easily into a black powder. The wool fiber is also self-extinguishing.
Plum Diamond Wool (has lycra)
Emerald Green Wool (100% wool)

b. Chemical Test- If wool is wetted with liquid chlorine bleach, it will first turn yellow and then slowly disintegrate from the action of the chemical. For this test, just pull out a few yarns and untwist them into individual fibers to provide maximum exposure to the bleach.


c. Your wool might be blended with silk, spandex, or other fibers. If you have a blend, it is much more difficult to determine what the fiber content is. 

3. Are there any special sewing techniques needed to sew with lighter weight wools?

a. Remember to use the proper weight of interfacing to stabilize the fabric

b. Matching the fabric weight to the garment design is critical

c. Even though it is lightweight, tropical weight wool still sews and handles beautifully when constructing garments. 

There are many variations of wool fabrics besides Merino wool. For example, Shetland wool, Debouillet, Southdown, Columbia, Romney, and Lincoln. These are all wool fibers with varying degrees of fineness.

Want to learn more? Maybe the next posting!! Happy Sewing!!

Beverly Kemp-Gatterson is a professor of fashion design, textiles, and apparel and a published author.  Her hobbies are sewing, perfecting couture techniques, reading, and dancing. She has taught fashion design and retailing at the Art Institute of Houston for the past seven years and is now also teaching an on-line course at the University of Texas at Austin in Retail Math. She holds a B.S. in Textiles from University of Texas, M.B.A. in Management from University of Houston-Victoria, and a Master of Science in Textiles from Virginia Tech.



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