Yarn is usually made by either animal fiber, plant fiber, synthetic fibers or a mixture of the various fiber varieties. Each fiber has different properties and often they are mixed to produce the best from each fiber. A coarser yarn is stronger and more durable while a finer yarn is softer.
What the yarn is made of affects how it looks, its properties and the price. Therefore, yarn made from natural material is usually slightly more expensive than synthetic fiber yarn. Which yarn is preferred is entirely up to you. It should feel good and look good and at the same time it should fit your wallet.
Sheep wool is a natural functional material that breathes and warms even when it has become wet (unlike cotton which gets very cold when it is wet). Therefore, wool is especially suitable for winter accessories such as mittens, hats and socks, which are often wet in our Swedish winter weather. Wool that can be washed in a machine (so-called superwash) is treated chemically to minimize the fuzzy outer layer of the fiber. Then you unfortunately get rid of the wool's fantastic properties, but you have a garment that many feel less prickly than ordinary wool. Unfortunately, garments usually made with one felting yarns have a hard time keeping shape, it tends to be stretched, this being because the yarn has been treated in a way that prevents the yarn fibers from sticking together.
merino wool is a type of sheep wool that is more exclusive than ordinary sheep wool. It consists of soft, slightly wavy fibers. The merino wool is divided into three general groups; strong, medium and fine. Fine is then further divided into superfine and ultra fine. The finer (thinner) fiber the merino wool has, the more exclusive it is. Merino wool itches less than regular wool and bacteria does not thrive in the wool which makes it ideal for underwear and socks.
Alpaca has a similar fiber to the sheep wool but it is soft like merino wool, it is because the fiber has a much smaller diameter than the coarse sheep wool. The alpaca wool is a luxurious, silky and durable fiber. It is not so easily felt and does not get snug. Depending on how you spin the wool, the yarn becomes light or heavy. Since the alpaca wool does not contain lanolin, it is hypoallergenic.
Mohair comes from Angora goats and is a luxurious fiber. It heats like wool but is very light. Mohair yarn is durable, nice to dye and does not weave. Although mohair is a hard fiber, it becomes very soft and fluffy when you spin it. It is not as elastic as sheep wool. You often mix up mohair with sheep's wool or nylon to keep the fibers together better.
Cashmere comes from the stomach of Kashmirget. This yarn is considered to be the most luxurious. The hair is combed by the goats once a year, so they are not cut. It is very soft, holds the heat and is elastic. Since production is so limited, it is an exclusive yarn.
Silke The silk fiber is one of the strongest natural fibers available. The yarn that is created becomes fantastically luxurious, soft and light but at the same time very durable. You often mix silk with wool, alpaca or cotton to give a lovely shine and fine case. Silk does not absorb heat so well, which is why it is popular in warmer climates. Because the production is so demanding, silk is expensive.
Cotton is a strong, non-elastic fiber that breathes. It is often used to make smooth, light summer clothes and is perfect for amigurumi ice cream and interior decoration. Cotton yarn is weaker than silk yarn but stronger than wool yarn. If the cotton yarn has gone through one mercerising treatment it will be smoother and glossier than regular cotton. It also gets more luster and doesn't shrink as much. The process was invented by John Mercer and involves treating the cotton with baking soda and stretching it.
Linen is more comfortable to wear than pure cotton garments when it is warm outside because it absorbs moisture and dries much faster than cotton. The lingerie is perfect to use for summer clothes and it gets finer, softer and more comfortable over the years. Just like cotton, flax does not have elasticity, it becomes easily wrinkled but you do not notice it in the same way when it is a hand knit garment. The yarn is usually thin spun because the fiber is so heavy.
Bamboo just like cotton gives a cool feeling. If you work with bamboo yarn it will be soft and light garments. It is also good for the sensitive skin, easy to wash and has antibacterial properties. Therefore, it is popular to use for baby projects.
Lyocell / Tencel is designed to find a more sustainable alternative to cotton. Lyocell and Tencel are the same, but the latter is a registered trademark. In the manufacture of Tencel, the wood raw material used is FSC-labeled, ie sustainability certified. Tencel is more gentle on the environment than both viscose and cotton. The cellulose fiber is made exclusively of pulp of eucalyptus trees. The only chemical used in manufacturing is a non-toxic solvent, amine oxide, which is used in a closed process where up to 99% of the chemical is recycled. This minimizes the impact on the environment and saves both energy and water. It is also said that Tencel is the absolute best for the sensitive / allergic skin.
The most well-known synthetic fibers are acrylic, nylon and polyester. They are easy to care for, do not stretch and are usually cheaper than natural fibers. Disadvantages of acrylic are that the material does not breathe, that it has the ability to grate during the work and that it can easily snap. In recent years, a lot of premium acrylics have come and many varieties are soft and not soft.
Acrylic and polyester has many advantages. It is easy to use for the beginner, does not wrinkle, is more elastic than cotton yarn and very compliant to crochet / knit. If you are allergic these yarns usually work well. They are economical to produce, easy to handle and very versatile. Often, you combine acrylic with ex cotton or wool.
Nylon / polyamide is very elastic, easy to maintain and durable. It is therefore mixed with other fibers to provide durability to clothing, such as socks and finger tips.