Choosing yarn for a project is not an easy task. The right yarn will make all the difference between a piece that you love and wear all the time, from one you never use. The two major things you need to consider, before purchasing your yarn, is its weight and the fiber content in it. In this post we will talk about the most common fiber categories and their characteristics. (You can learn more about the yarn weights in this post: Understanding Yarn Weights).

Yarn Fiber Categories

The fiber content of the yarn plays a major role in your project. It will affect how the finished piece looks, how it wears and how it should be cared for. The two main fiber categories are Natural Fibers, that come from animals or plants, and Synthetic Fibers, that are manufactured from various materials. Yarns that combine two or more types of fibers called Blends. Blends are produced to make the best use of the properties of various components of each fiber type.

Animal Fibers

As the name suggests, animal fibers are sourced from animals. They are naturally occurring fibers that are generally composed of proteins. Animal fibers are perfect for garments and cold weather accessories since they are warm and soft. 

Let’s see some of the popular types of animal fibers: 

Wool is made from the fleece of sheep and it’s the most common fiber used for yarn. Wool is warm, breathable, and has high insulating and moisture absorption. It is durable and elastic, meaning that if it is stretched, it will retain its shape. Some of the downsides of wool are that it is prone to pilling and it can be itchy and cause allergic reactions. There are many variations of sheep breeds that produce various types of wool like Merino, Shetland and Icelandic wools.

Alpacas are native to South America and they are camelid mammals. There are two breeds of alpaca: the Suri (softer and silkier fibers) and the Huacaya (wool-like fiber) which are the most common ones. Alpaca fiber is strong and durable. It is very lightweight, warm and comfortable, it also lacks lanolin and that makes it hypoallergenic and perfect for babies or sensitive skin. The downside of alpaca is that it doesn’t have stitch memory and it can grow and stretch out. 

Cashmere is a luxury fiber that is obtained from cashmere goats. Cashmere fiber is weaker than wool but is warmer and highly insulating. It is also lightweight, soft and drapey. The disadvantages of Cashmere are its prone to pilling, the lower stitch definition and its price, since it is one of the most expensive yarns. 

Angora fiber comes from angora rabbits and it is one of the most expensive yarns on the market. Angora fibers are thin and luxurious soft, they are fluffy and much warmer than wool. It is often mixed with other types of wool to give the yarn elasticity, as is not naturally elastic. Also it doesn’t have stitch definition, it sheds and It can be slippery and difficult to knit with.   

Mohair is a fuzzy, silky yarn made from the hair of the Angora goat. It is durable, warm and light. It is often blended with other wools to add its properties to the final yarn. Mohair fibers are also absorbent and breathable. On the downside mohair is difficult to knit due to its fuzziness and it can be irritating to the sensitive skin.

Silk is obtained from cocoons made by the larvae of the silkworm and is very smooth and shiny. Silk yarn is strong and durable, it is exceptionally soft and drapey and has excellent stitch definition. On the other side silk is very slippery to work and it can be prone to snagging. Silk has no elasticity and it can stretch and distort the project. One final disadvantage of silk is that it can attract moths.

Plant Fibers 

Plant fibers have been obtained from various parts of plants including leaves, stems, fruits and seeds. Plant fibers are less elastic than Animal fibers but they are stronger, more durable and breathable. They are easy to care for and they are preferable for spring and summer.

Let’s see some common plant fibers: 

Cotton is a soft, fluffy fiber that we get from cotton plants and it’s been used since ancient times. It is inexpensive, globally available and easy to care for. Cotton fibers are smooth, strong and breathable. It has great stitch definition and it’s exceptional  for summer wearables, dishcloths or toys. It is also a great alternative option for anyone that suffers from allergies to animal fibers or has sensitive skin. Cotton’s biggest disadvantage is the lack of elasticity and stitch memory; it can stretch out and sag, distorting the project. 

There are various types of cotton yarn:

  • Egyptian Cotton: Very soft yarn with smooth texture and long fibers. These yarn are resistant to fraying and pilling. 
  • Pima Cotton: Pima cotton yarn is extremely similar to Egyptian cotton but is primarily grown in the United States. 
  • Mercerized cotton: Mercerization is a chemical process that strengthens the fibers and improves how well it holds dye.
  • Recycled cotton: Recycled cotton yarns are made from recycled fabrics.

Linen yarn is made from the fibers of the flax plant. Linen is stronger, more absorbent, and dries faster than cotton. It’s breathable, thin and has good drape. Linen is easy to care for, it’s machine washable and it will soften with washing. It is comfortable for hot weather, but it creases and wrinkles very easily and has low elasticity.

Hemp fiber is derived from the hemp plant and is considered as one of the strongest natural fibers. Hemp is suitable for warm weather, it’s very durable, easy to care for and just like linen will soften with each washing. It has good stitch definition and does not wrinkle, but it has a straw like appearance, it’s stiff and has no elasticity.

Bamboo is one of the fastest growing plants in the world. Bamboo fiber is lightweight, has a nice sheen, and its drapey. It is also breathable, antibacterial and reflects UV rays. On the downside bamboo is less durable and it can be expensive.

Synthetic Fibers

Synthetic fibers are made by humans using a chemical process. These fibers are cheaper and easier to mass- produce than the natural ones. They are also more durable, water and stain resistant. 

Let’s see some examples of synthetic fibers: 

Acrylic is the most commonly used synthetic fiber and it is a cheaper alternative to a lot of natural fibers. Acrylic is soft, durable and warm like wool, but it lacks wool breathability and insulating. The low cost of acrylic makes it ideal for new crafters who want to practice and because it is machine washable and hyperallergic it is also a great option for baby items.

Nylon is very smooth and shiny with a lot of drape and it’s a cheap alternative to silk. Nylon fiber is incredibly strong and elastic, it is easy to care for and machine washable. It also resists abrasion but pills easily. Nylon fibers are usually blended with natural fibers to increase their durability and resilience. On the other side nylon fibers can be uncomfortable when worn next to the skin and they are heat sensitive meaning that high heat can melt the fabric.

Polyester is durable, smooth and shiny, it resists wrinkles and it holds its shape. It is usually blended with other fibers to add strength. It is easy to care for and it is machine washable, however polyester fibers are not breathable and they can feel scratchy on the skin.

Rayon is made from plant fibers but it is considered Semi-Synthetic as it goes through a chemical process to form the yarn. Rayon can imitate the feel and looks of oher fibers like silk and wool, it is soft, silky and has excellent drape. It is also strong and durable, but it doesn’t have elasticity and it can’t hold its shape. Rayon doesn’t have insulating properties making it ideal for the summer months.


Most of the yarns you will find in the stores are blended. Fiber blending is used to improve the characteristics of a yarn. For example nylon fibers are added to wool to make it more durable, or silk is blended with other fibers to add shine and drape.


So, you have learned a few things about the yarn fibers but how to choose what is best for your project?

The best thing to do, when you are a beginner, is to practice with many different fibers. That way you will learn how each fiber feels and behave, what to use for specific projects and most importantly you will discover what types of fibers you love to work with.  

When you are following a designer’s pattern, you should try to use the yarn that the pattern suggests. If that’s not possible, then try to find a yarn with the same fiber and weight as the suggested yarn. This way you will have a finished project similar to the original. You can always choose a yarn with different fiber or weight than the pattern calls for, but you should have in mind that your finished project might be quite different from what you aimed for.

When you don’t follow a pattern and want to create something by yourself, you have to answer a few questions: Who will wear the item? Is it for a baby, for someone with sensitive skin or allergies? Do you need the item to be machine washable? Is it for warm or cold weather, should it be breathable? What kind of texture do you want to achieve? 

Think about these questions but don’t forget, you should always make a swatch before starting on a new project, even when you are following a specific pattern. This way you will know how your yarn feels and what your gauge is.

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