There are different varieties of knitting yarns. Yarn is a continuous strand of interlocked fibers, suitable for use in the production of textiles, sewing, crocheting, knitting and weaving. While yarn is any fiber used to construct a fabric, thread is any fiber used to sew two pieces of fabric together. The various types of knitting yarn are distinguished by their weight, purpose, ply, source fiber, texture, color, and pattern. Knitting yarn can be made of natural or synthetic fiber. While cotton, linen, hemp, wool, and silk are natural fibers, synthetic yarns refers to man-made fibers like rayon, polyester, acrylic, nylon, acetate, spandex, polypropylene etc.

Let us know more about the types of knitting yarn as follows:

• Natural Fiber
• Synthetic Fiber

Natural Fiber
Natural fiber as the name suggests, is the fiber derived from nature, be it animal, plant or vegetable. Important natural fibers are obtained from various natural sources like cellulosic fibers obtained from the seed hair, stems, and leaves of plants or protein fibers obtained from the hair, fur, or cocoons of animals. There are also mineral fibers procured from minerals. However, animal and vegetable fibers are the two important natural fibers used in making knitting yarn. Let us know more about natural fibers for knitting yarn under the following categories:

• Animal Fiber
• Vegetable Fiber

Animal Fiber
Animal fibers are produced by animals or insects, and are composed of protein. There are two animal fibers recognized worldwide as major textile or knitted fibers. They are Wool and Silk. But there are other varieties as well. There are several animal fibers and each is obtained from a different source. The various varieties of animal fibers are as follows:

• Wool
• Mohair
• Angora
• Cashmere
• Camel
• Alpaca
• Silk

Wool
Wool fiber grows from the skin of sheep and is relatively a coarse fiber. It is crimpy (wavy) and has scales on its surface. Depending upon the breed of sheep, the appearance of the wool varies. There are some fibers having a great deal of crimp, and smaller, finer scales while there are others having little crimp, and coarser scales. Two striking characteristics of wool are its susceptibility to heat and its felting property, which is caused by the scales on the surface.

Mohair
This fiber is from an Angora goat. It is durable, sheds dirt, dyes well and does not felt easily. Despite its hardiness, the mohair fiber is usually spun into yarn used for fluffy garments and scarves. The yarn is abraded, roughing its fibers to create a "fuzzy" look.

Angora
This is a fiber from rabbits. Fabric made from this yarn is inelastic, that is, there is no stretch. The fiber is very fluffy, soft and warm.

Cashmere
This knitted fiber is from the undercoat of a Cashmere goat. It is very expensive because only a few ounces are obtained from each goat per year. It is also a delicate yarn. The fiber is more fragile than wool and more susceptible to abrasion. This means that it is usually blended with wool to make it more durable.

Camel
The fiber is obtained from the two-humped or Bactrian camel. Camel hair cannot be bleached. Hence it is either used undyed or dyed a darker color. The fiber is lightweight and fragile.

Alpaca
The fiber is obtained from the Alpaca which is a domesticated breed of South American camel like the Vicuna. Yarn from the alpaca fiber does not felt or pill easily. The alpaca fiber comes in 15 natural colors. The fiber is denser than wool, so fabric knit from it may droop.

Silk
Silk fiber is a fine continuous fiber produced from the cocoon of a moth caterpillar known as the silkworm. While silkworm is cultivated, the wild or tussah silk is obtained from uncultivated silkworm cocoons. Silk fiber retains heat, absorbs moisture, very strong and very stable when knit, neither shrinking nor stretching.

Vegetable Fiber
There are various varieties of vegetable fibers, found in the cell walls of plants or vegetables. Of all the varieties, two are recognized as major knitted or textile fibers. They are cotton and linen. Vegetable fibers are composed mainly of cellulose and can be classified into short fibers or long fibers. We discuss below the various varieties of vegetable fibers:

• Cotton
• Linen
• Ramie

Cotton
It is the fiber surrounding the seeds in a cotton pod. It is composed of 90% cellulose and about 6% moisture. Cotton is usually white in color but there are green and brown varieties as well. The fiber is dense, heavy and inelastic. Cotton fiber makes a weaker yarn than silk or linen but is stronger than wool. Cotton yarn is used to make fabrics that are universally used for all types of apparel, home furnishings and industrial applications.

Linen
Linen fiber is derived from the stalk of the flax plant. The fiber is durable and stronger than any other fiber. Linen fiber is relatively soft, straight and lustrous and becomes more beautiful with age. The fiber absorbs moisture better than cotton and dries more quickly which makes it more comfortable to wear in hot temperatures than cotton.

Ramie
Ramie (Boehmeria nivea) is a flowering plant in the nettle family Urticaceae, which is native to eastern Asia. Ramie is one of the oldest fiber crops and is principally used for fabric production. This fiber is often used as a substitute for linen because it is less expensive and shares linen's good qualities.

Synthetic fiber
There are various varieties of synthetic or man-made fibers. Man-made or synthetic fibers are derived from various sources. Synthetic fibers are chemically processed and changed in form and several other characteristics into fibers of different lengths. Synthetic fibers are created from other sources like mineral fibers, metallic fibers and rubber fibers. Some of the popular varieties are as follows:

• Rayon
• Nylon
• Polyester
• Acrylic
• Spandex

Rayon
Rayon is a fiber produced from natural ingredients but by artificial means. In other words, rayon is an artificial fiber but not truly synthetic. Cellulose from wood pulp or cotton is treated chemically till it is drawn into filaments. Rayon is a weak fiber. However, the fiber is absorbent, dries quickly, and stretches. There are two principal varieties of rayon which are now commercially produced. They are: viscose and high wet-modulus.

Nylon
This fiber is lightweight, elastic, strong, resists abrasion, does not stretch or shrink and is easy to wash. The fiber is usually combined with wool to impart its strength and elasticity to the wool. The nylon fiber was the first commercially successful polymer and the first synthetic fiber to be made entirely from water, air and cold. There are various forms of nylon fibers which depend upon the chemical synthesis.

Polyester
This is the most common type of synthetic fiber. Polyester fibers are thermoplastic. Fabric made from it retains its shape and adds strength and resilience to natural fibers. This fabric is very easy to wash and is more comfortable to wear than many other synthetics.

Acrylic
Acrylic is the most common synthetic fiber in knitting yarns. The fiber is resilient, moderately strong, somewhat inelastic, and it feels good to the hand and is light in weight. Acrylic fabric is easily made to imitate natural fibers so they are sold as a substitute to wool. Acrylic is often used to achieve novel textures and characteristics that are not available in natural fibers.

Spandex
Spandex is another popular type of synthetic fiber. Spandex fibers are extremely elastic and they are used for various purposes as foundation garments, hosiery, sportswear and swimwear.