Yarn Glossary

A glossary of terms in alphabetical order for yarn construction, fiber qualities, and associated terms. If you see a term that you don't know, it may also be defined here. Is there a term you would like to be defined here? Email us at hello@blacksquirrelberkeley.com.

We also have glossaries for spinning terms click here (coming soon) and natural dyeing terms click here (coming soon).

Learn more about sheep breeds, other fiber animals (coming soon), and plant fibers (coming soon).

4-ply: a term used in some countries to refer to fingering weight yarn.

8-ply: a term used in some countries to refer to DK weight yarn.

Acid Dyes: Acid dyes are generally synthetic dyes developed since the late 1800's and are the most common dyes used to dye wool. Prior to acid dyes, natural dyes were the most common dyes.

Acidic: Having a low pH below a pH of 7.

Alkaline: Having a high pH above a pH of 7.  Sometimes referred to as basic.

Animal Fibers:  Commonly used animal fibers are Alpaca, Llama, Wool, Mohair, Silk, Yak, Camel, Angora. Other animal fibers are used though often they are rare and may be very expensive. These include Bison, Qiviut, Vicuña, Possum (from New Zealand). Information on fiber animals coming soon.

Balanced Yarn: A balanced yarn is one where the twist in the singles is matched by the twist in the plying. It will not twist upon itself if you hold two ends of a short length together.

Barber Pole Yarn: A yarn made from plies of two different colors.  Also known as a marled or ragg yarn.

Bast Fibers: Bast fibers are collected from the phloem, the inner bark of some plants like flax (linen), hemp, ramie, jute, and sisal. A process called retting is used to separate the bast fibers from the other components of the plant. Bast fibers are very strong and durable. They tend to soften with use and washing while remaining strong.

Bleeding: Color rinsing out of a finished garment, yarn, or fiber. Bleeding can be excess dye that was not fully rinsed out or dye that was not properly set on the fiber. Indigo is an exception, see crocking. Things dyed with acid dyes can be heated with vinegar or another acid to try to set the dye. For naturally dyed things, vinegar is NOT recommended. It will not set the dye and it may shift the color in a way that cannot be corrected. If you are worried about the colors bleeding, use a color catcher when washing to collect any stray dyes. It is always wise to squeeze newly soaking items to check for bleeding and to keep your soaks short if you suspect bleeding. See our washing instructions for more information.

Blown Yarns: Blown yarns are not spun. Instead a loose netted tube is made, usually from nylon or cotton, and fibers are blown into the tube. Blown yarns tend to have excellent yardage and warmth while being very light. They also have a fuzzy halo texture similar to carrying alpaca or mohair with another yarn and decreased stitch definition due to the fuzziness.

Cable(d) Yarn: A cabled yarn is plied and then plied again against another plied yarn or singles yarn. Cabled yarns give wonderful stitch definition to knit fabric and tend to pill less.

Cake: see yarn cake

Carded: Fiber that has been prepared on hand cards or a drum carder. Often this means the fiber has not been combed to remove the shorter fibers. Carded wool is considered a woolen fiber preparation and makes a woolen spun yarn.

Cards: see hand cards.

Cellulose Fibers: Plant fibers are also known as cellulose fibers. They can be natural like cotton, linen, and hemp. Or they can be rayons that use plant cellulose to create a manufactured fiber.

Chainette / Chain Yarns: Chainette yarns are made with a very fine strand worked into a tube similar to an icord. This means there is a lot of air trapped in the tube making it a warm yarn. It also means that it takes less fiber to make the yarn so your skein will have generous yardage. Using a fine strand also gives the yarn additional strength and make sit much less prone to pilling though it is more prone to snags. It can add a bit of elasticity to fibers like linen that aren't otherwise elastic. Expect stitch definition to be less defined with an overall subtle texture.   

Citric Acid: An acid found in many vegetables and fruits, but most notably in citrus fruits. It is used to neutralize the high pH of indigo dyed fibers, as a conditioner for protein fibers, and when dyeing with acid dyes.  

Color Catcher: Color catchers are commonly available in the laundry aisle of supermarkets. They are designed to catch excess dye that comes out while washing to keep it from bleeding onto other colors. Note that prolonged soaking with a color catcher may not help as the excess dye may not be coming into contact with the color catcher but is contacting other parts of the project. Gently stir soaking items occasionally to ensure the color catcher works. See our washing instructions for more information.

Combed: Fiber that has been combed to remove short fibers and to align the fibers into a worsted preparation. The fibers will be straight and aligned without crossing. Worsted spun (not to be confused with worsted weight) yarn is always combed.

Core-Spun Yarns: Core spun yarns use a strong core, often a synthetic fiber, and wrap fiber around the core at an almost perpendicular angle. They tend to be thick and soft.

Crocking: Crocking refers to blue indigo dye that comes off during spinning or knitting.  Indigo in this state cannot stain anything washable like skin or clothing.  It may stain wood or bamboo needles, as they are porous and not usually washable.  Crocking will decease with time. 

Direction of Twist: Yarn can be spun or plied clockwise or counterclockwise. The direction refers to the direction the yarn was spun. Clockwise yarn has a Z-Twist. Counterclockwise yarn has an S-Twist. You can see the direction by holding up a piece of yarn. An S twist will lean to the left \ like the vertical stroke of the letter S. A Z twist will lean to the right / like the vertical stroke of the letter Z.

Dual-Coated: An animal that has two coats of fiber. Guard hair sheds water off of the animal protecting the soft fine down coat underneath. Primitive sheep breeds are dual-coated as well as yak, bison, camel, cashmere, and llama. Most hand knitting yarns are from animals that don't have guard hairs or have had the guard hairs removed during the fiber preparation. See our information on sheep breeds; information on other fiber animals coming soon.

Dyed in the Wool: see heather.

Fast or Fastness: A fast color will not fade due to exposure to light or washing. All colors will fade eventually, especially with prolonged exposure. When a color is called fast this means it will not fade quickly under normal conditions.

Felt: Wool that has been felted, usually into a sheet or a three dimensional shape.

Felting: The process of locking wool fibers together. The scales on the individual wool fibers will interlock creating a bond that will not come undone. Wool can be wet felted, usually with heat, soap, and agitation. It can also be needle felted. Knit, crocheted, or woven fabric that is felted shrinks quite a bit and the individual stitches/woven patterns are discernible. Also see fulling below. Superwash wool and cellulose fibers will not felt.

Fiber: Any number of animal or plant fibers that can be spun such as wool, mohair, alpaca, silk, hemp, and bamboo. Animal fibers are protein fibers and plant fibers are cellulose.

Fiber Diameter: The diameter of an individual fiber, usually measured in microns. See grade for other systems.

Fleece: The shorn wool from a sheep. When done right, it is intact and can be laid out in one piece. The quality of the wool varies with the leg and belly wool being the lowest quality. It is usually removed in a process called skirting and not used in yarn and fiber production.

Fugitive Color: A color that is not fast. Fugitive colors will fade quickly, sometimes in a matter of hours. Commercial dyes are never fugitive.

Fulling: Similar to felting only the process isn’t taken as far; you will still be able to see individual stitches. Sometimes yarns are fulled to make them a little more stable and less likely to shed, or to achieve a desired look. Knit or crochet fabric may be fulled for the same reasons or by accident. Fulled items, like felted items will shrink and cannot be undone. Superwash wool and cellulose fibers will not full.

Grade: There are three systems used in the United States for grading wool. The Blood System defines the fleece by the amount of merino blood in the sheep. Since there isn’t a direct correlation between the amount of merino blood and the fineness of the fleece, it is an inexact measure.

The second is the Bradford Count. It is an estimate of the number of hanks that can be spun from a pound of wool. The idea is that a finer wool can spin a finer yarn. This is also an inexact measure.

The third is the Micron Count system. The wool fibers are measured under a microscope.  The unit of measure used is microns, which are about 1/25,400th of an inch. This system is the most exact system.

Grist: The thickness (diameter) of the yarn. It is similar to the yarn weight such as fingering, sport, worsted, bulky, etc.

Handspun: Yarn that has been spun by an individual on a spindle, wheel, or charka.

Hank: A loop of continuous yarn that is usually twisted. Yarn in a hank form must be wound into a ball or yarn cake before using.

Heather: Yarn that is a blend of different colors. The colors are well blended to give a heathered appearance. This is often called dyed in the wool as the fiber is dyed and blended before it is spun.

Kemp: Brittle, coarse wool fibers that do not take dye. It is most often found in belly and leg wool.

Lanolin: A fatty wax created by sheep and commonly called grease, as in the common name for an unwashed fleece being called a grease fleece.

Marl(ed) Yarn: A yarn made from plies of two different colors.  Also known as a ragg or barber pole yarn. Marled yarn effect can also be created by holding two or more different yarns together and working them as if they were one yarn.

Mawata: A silk hankie (note to be confused with woven hankies) made by stretching silk cocoons over a frame.  A mawata or hankie is a stack of silk squares, each square is made from an individual silk cocoon. It is similar to a silk cap where each cocoon is stretched over an oval form resulting in a shape that resembles a hat or cap. Mawata can be stretched out to an unspun yarn for knitting.

Memory: Memory is the ability of a fiber to be stretched and then return to its original shape. Non-superwash wool has memory. Plant (cellulose) fibers, silk, and synthetic fibers have little memory. Superwash fiber has some memory as the superwash process reduces wool's memory.

Mercerization: The process of treating cotton, linen, and hemp yarns in a sodium hydroxide bath and then neutralized in an acidic bath. The result is a stronger, more lustrous yarn that takes dyes more readily.

Micron Count: The average fiber diameter measured in microns (1/25,400th of an inch). Superfine fiber is below 18 microns, fine fiber is between 18 and 21 microns, medium grade fiber is between 22 and 30 microns, and coarse fiber is above 30 microns. For reference, human hair ranges between 50 and 120 microns with an average of 70 microns.

Natural Dyes: Dyes made from natural substances, usually from the bark, leaves, roots, flowers, or wood of a plant. There are also insects, notably cochineal and lac, that make dyes.

Needle Felting: Yarn and wool fiber that is non-superwash can be felted using very sharp barbed needles. Needle felting can be worked flat be creating designs on fabric or by making small three dimensional shapes.

Nep: Neps can be naturally occurring or introduced. They are short or knotted fibers that create textured yarns. Naturally occurring neps are short fibers or weak tips that have broken off. These neps are removed when combing fiber to make a worsted preparation. Sometimes neps are added (or retained) to make a textured yarn. Introduced neps are often recycled bits of synthetic fibers used to add color texture to a yarn (creating a tweed yarn). The fibers are selected for their inability to take dye so they retain the original color(s).

Niddy-Noddy: A tool for winding yarn into hanks.  Usually it makes a hank of a specific circumference like 1 or 2 yards so it can also be used for counting yardage.

Non-superwash: Wool that has not been treated to make it superwash. Non-superwash yarn is often considered better for garments like sweaters as it has better memory (will retain its shape) and maintains the beneficial properties of wool that are lost in the superwash treatment. Wool has many wonder properties; it is: anti-microbial, fire resistant, able to hold 30% of its weight in water while remaining warm, mildew resistant, biodegradable, breathable, and odor resistant. See superwash and wool.

Nøstepinde: A tool shaped like a dowel for winding a center-pull ball of yarn.

Over Dye: When one dye is dyed over another. Indigo is often used as an over dye.

pH: A scale for measuring the alkalinity or acidity of a substance. A pH of 7 is neutral. Low pH is acidic; high pH is alkaline.

Plant Fibers: Plant fibers come from plants rather than animals. Plant fibers can be one of 4 types: seed fibers (cotton), bast (linen, hemp), leaf (sisal), or husk (coconut). Typically only seed and bast fibers are used for the hand knitting/crocheting and handspinning markets. Some fibers commonly considered plant fibers are actually rayons made from plant cellulose. Examples of these rayons are bamboo, Tencel, seacell, lyocell, and viscose. 

Ply, plies: When yarn is spun, it starts as a singles yarn; sometimes that is the final product. Usually 2 or more plies are spun together to make a plied yarn. If singles are spun clockwise (z-twist), they are plied counterclockwise (s-twist). If singles are spun counterclockwise, they are plied clockwise. This creates a balanced yarn that is easy to work with meaning it won't kink up as you work.

Ragg Yarn: A yarn made from plies of two different colors.  Also known as a marled or barber pole yarn.

Rayon: Rayon uses cellulose for various plants to create an extruded fiber. It is an industrial product made from plants. There are many types of cellulose used and rayons have many names. Viscose is the most common type of rayon. Lyocell / Tencel (TM) uses wood pulp cellulose, Bamboo, Modal uses beech tree cellulose. Traditionally, rayon production uses a lot of harsh chemicals and creates a lot of effluent, both of which are harmful to the environment. There are some forms of rayon that are more environmentally friendly but are not typically found in the yarns available to yarn stores and hand crafters.

Roving: Carded or combed fibers prepared in a long strip usually about 1-2 inches wide. This is drafted thinner to become yarn either at a woolen mill or by a handspinner.

S-Twist: Counterclockwise spun singles or plied yarn. The direction of the twist is the same direction as the middle stroke of the letter S.

Semi-Worsted: A yarn that is woolen spun from a worsted preparation. This yarn has some of the properties of a fully worsted prepared yarn like greater abrasion resistance and a smoother yarn and some of the properties of a fully woolen prepared yarn like being warmer and lighter weight with a more rustic texture.

Silk: Silk is a filament that is extruded by moth caterpillars to form a cocoon. Most silk used in yarn is mulberry silk from the mulberry silkworm, Bombyx mori because their silk is white. White fibers are often preferred by larger yarn manufacturers as they are easier to dye to a desired color. Silk is strong with tremendous shine and drape. Another silk found in yarn is tussah silk sometimes called wild silk. Tussah is naturally a darker color because the worms eat leaves high in tannin which imparts a honey brown color in the silk.

Singles: A single strand of fiber twisted together. Singles refers to a yarn comprised of one ply. These yarns are called singles yarn and traditionally the term is always plural, even when though there is only one. Now it is often called single-ply.

Skein: Yarn wound into a ready to use put up. A skein can have a round, donut, or a cylindrical shape. Often hanks are called skeins.

Skein Winder: A tool for winding hanks of yarn into cakes of yarn so they are ready to be used. They are usually used with a swift. 

Skirting: The process of removing the lowest quality (and usually the dirtiest) wool from a freshly shorn unwashed fleece before processing the wool into fiber and yarn.

Slub Yarn: A yarn with sections that are thicker and have less twist or where one ply is built up in one spot to create a bump.

Sock Yarn: A yarn designed for hard wear. It should be a worsted spun yarn and will often contain nylon for added strength, especially in yarns made with fine wool like Merino. Alternatives to nylon are mohair, silk, and wool with a higher micron count (coarser and therefore more durable) and / or a longer staple length.

Staple or Staple length: The length of the individual fibers. Wool can have a staple of 2-8 inches, usually is 2.5 - 5 inches; alpaca 3.5 - 7 inches; cotton is 3/4 - 1.5 inches; mohair is 6-12 inches; cashmere is 1.25 - 3 inches; and yak is 1.25 inches. Synthetic fibers are extruded and cut to the length desired for the production process.

Swift: A tool that holds a hank of yarn so it can be wound into a ball. Swifts can be collapsible such as an umbrella swift or have pegs that can be adjusted for different diameters of hanks.

Superwash: Wool that has been treated so it will not felt or full. Usually this process involves striping or dulling these scales followed by a polymer coating to coat the fibers. Caustic chemicals are used in this process and it is often done in countries that have lower environmental standards. Superwash wools tend to be softer due to the scale removal and take colors more readily giving us brighter and deeper colors than non-superwash wool. Superwash wools contain and can shed microplastics.

Superwash wool loses many of the beneficial properties of wool. It tends to stretch out and not retain its shape. It also loses much of its antibacterial, antimicrobial, and insulating properties. It needs to be washed more often for garments to regain their shape and because it doesn't resist dirt and odors as well.

Synthetic Fibers:  Fibers like polyester, acrylic, and nylon are manufactured petroleum products. Also see rayon, a synthetic fibers made with natural plant cellulose.

Umbrella Swift: A swift that opens and closes similar to an umbrella.

Vegetable Matter or VM: Straw, hay, seeds, or burrs in a fleece or prepared fiber.  Most VM (not burrs) will fall out during spinning. All wool has some VM in it before processing. Yarns without any VM have been treated to chemically burn out the plant matter which can harshen the wool and create pollution. We choose to view vm as a good thing, as wool that has been minimally processed and an indicated that it is a more environmentally responsible product.

Wool: The fiber from a sheep. Wool has wonderful natural properties. It is a great insulator keeping you warm in cold weather and cool in warm weather. It is even warm when wet up to 30% of its weight. It won't even seem wet until it holds 60% of its weight in water. The lanolin in wool makes wool antibacterial and antimicrobial while easy to care for. Wool resists stains and gives up dirt easily when soaked. It is also stronger and more durable than other clothing fibers and fire resistant.

Each strand of wool is covered in scales. These scales can interlock causing fulling or felting. This is especially true when they are agitated or heated which causes the scales to separate and be more susceptible to fulling and felting. These scales have benefits too. They give wool a bit of grab which can be handy for colorwork as the yarn grabs its neighbors and blooms with washing to fill any gaps.

Almost all domesticated sheep must be shorn annually as the wool will keep growing. In time this will become heavy, matted, and pose serious health and comfort risks to the sheep. Learn more about sheep here.

Woolen Preparation:  Fiber prepared in a way in which the fibers are not aligned. Most commonly by carding. Handspinners do this with hand cards or drum carders. Mills do this with very large drum carders.

Woolen Prepared Yarn: Yarn that starts with a woolen preparation and that is also woolen spun. Since the fibers are not aligned, there are more air pockets within the yarn making it warmer and lighter weight with a more rustic texture.

Woolen Spun: Woolen spun yarns are made from woolen fiber preparations. They have more loft and warmth due to air pockets caught inside the spun yarn because the fibers are not aligned. Yarn spun in a woolen method such as long draw.

Worsted Preparation: Fiber prepared so that the fibers are aligned and straight and the short bits and neps have been removed. A worsted preparation tends to create a smoother, denser yarn that is less likely to pill or felt and is more abrasion resistant.

Worsted Spun: Yarn spun in a worsted method with fiber that was processed with a worsted preparation. Worsted spun yarns are dense and durable as they can generally tolerate more abrasion than a woolen spun yarn. Sock yarns are typically worsted spun as socks get a lot of hard wear compared to other garments.

Worsted Weight Yarn: Can be worsted or woolen spun yarn as worsted in this context refers to the thickness or grist of the yarn. Worsted weight yarns typically knit at about 5 stitches per inch (sts/in) or 20 stitches over 4 inches (10cm). See our yarn weight information here.

Wraps per Inch or WPI: The number of times yarn can wrap about a ruler or pencil. This is a way for spinners and knitters to estimate the grist or weight of a yarn (as in fingering, sport, worsted, or  bulky).

Yarn Cake: A center-pull ball made by using a ball winder. It can be used from either the end at the center of the cake or the outside end. It is called a cake because it is a short cylinder like a small cake.

Yarn Weight: Click here for more information on yarn weights.

Z-Twist: Clockwise spun singles or plied yarn. The direction of the twist is the same direction as the middle stoke of the letter Z.