People have been making yarns and threads for centuries. Although now commercialized products are put through a highly automated process, the basics are still the same.

Photo courtesy of Jeff Kubina
What is Fleece?
Most people associate wool with sheep. There are many other sources as well: llama, goat, alpaca, camel, et al. When these animals are sheared, or shaved, the product is called fleece. Fleece can also be obtained by plucking the excess fur from Angora rabbits or any other animal that sheds. This fleece must first be washed, dried, and then carded. Before washing it is referred to as raw fleece, after is it known as scoured fleece.
What is Carding?
Carding is the process of combing all the fibers of the fleece in the same direction. Think of it as similar to combing your hair. It gets rid of knots and tangles, and makes the hair smooth and silky. After the fleece has been carded it is known as roving.
Why is the Roving Spun?
To make yarn, roving is required to feed into a spinning wheel or drop spindle. The spinning process determines how thick or thin the yarn will end up being. It twists the roving tightly enough so it will not shed or break easily.
What is Ply?
Different yarns that have been spun once can be spun together, or plied. This adds to the strength, as well as gives the maker flexibility with colors and fibers. For example, you can ply a white alpaca yarn with a black sheep yarn. This will add interest to your color as well as combine the properties of the alpaca and sheep wools.
Making yarn from fleece is a very time consuming process. Some farmers send their wool to a spinnery to be washed, carded, spun, and dyed. The hobbyist can purchase fleece or roving if they want to try it themselves. There are now dying kits available to make your own colored yarns.