When you begin to learn about different dyes and dyeing techniques you will encounter many words that you have never come across before. This glossary of dyeing terms has been designed to provide a helpful summary.
| BC | DEF | GHI | JKL | MNO | PQR | STU | VW |
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| Dyeing Term | Definition of Dyeing Term |
| Acidity | See pH |
| Acid Dyes |  A synthetic dye formulated for best results on protein fibres such as wool, silk and hair and some synthetics including nylon (not polyester). The “acid” in the dye name relates to the acidity needed to set the dyes permanently i.e. white vinegar or citric acid. |
| Adjective Dyes | Adjective dyes (or Mordant dyes) are natural dyes that require a mordant to make colours permanent and washfast. Most natural dyes are adjective dyes. |
| Alder Buckthorn | Shades of yellow to brown can be achieved from the bark when used as a natural dye. This is a substantive dye meaning that a mordant is not required to extract the colour. |
| Alkanet | Alkanet root natural dye (also known as Alkanna tinctoria or Dyer’s Bugloss) dyes fibre to shades of grey through to purple. Extracting the dye using an alcohol will give red. |
| Alum Mordant | Alum mordant used to colour protein fibres (wool, hair and silks) with natural dyes, and in combination with tannin for cellulose fibres. Alum as a mordant links chemically with the fibre and creates attachment points which bond with the colourant from natural dyes creating light and washfast colours. It anchors the colour obtained from natural dyes and can be used to shift colours (depending on the natural dye used) to yellows, lovat, orange, red, and purple. Synonyms: Potash Alum, Aluminium Potassium Sulphate, potassium Alum |
| Aluminium Lactate / Aluminium Acetate | Natural dyes do not bond well with cellulose fibre in the same way as other fibres. These plant fibres were historically pre-soaked in a solution of tannin and then in alum over several cycles prior to dyeing to make the dye molecule attach to the fabric. Aluminium Lactate or Aluminium Acetate can be used as an alternative to tannin to fix natural dyes on cotton, bamboo, flax and tencel. The chemicals improve light and washfastness of all natural dyes and achieve intense, clear colours. |
| Aniline Dyes | Discovered by chemist William Henry Perkin, the first mass-produced chemical dye; Mauveine. Also known as aniline purple and Perkin’s Mauve, the dye was made from an extract of coal tar (aniline). This led to a range of brilliant colours that worked well on silk and wool. Due to their poor colourfastness, and the introduction of other, more superior synthetic dyes, aniline dyes fell out of popular use in the textile industry. |
| Annatto | Annatto seeds come from achiote trees from the Americas. The powdered seeds can achieve shades of spicy orange when used for natural dyeing. Although considered to be a substantive dye, the colour, washfastness and lightfastness are greatly improved with the use of mordant. |
| Batik |  See Resist Dyeing |
| Birch Bark | Birch Bark is capable of dyeing fibres from beige to various shades of pink. As it contains tannin the dye does not need a mordant to make it bond with the fibre, however the use of a mordant will enhance colours and improve washfastness and lightfastness. |
| Bloodroot | Bloodroot (Sanguinaria canadensis) is a woodland plant which is used for both dyeing and medicinal purposes. As a natural dye it colours fibre to shades of red. Bloodroot is poisonous to both livestock and humans when ingested in large doses. |
| Botanical Printing | Also known as Eco Dyeing, this technique uses leaves and flowers to create prints on fabric and paper using Alum and Tannins. |
| Brazilwood | A red-brown natural dye. Brazilwood (Caesalpinia echinata) is a protected species of tree in Brazil and no longer available for use as a dye. The alternative, Sappan wood powder, is from Asian Brazilwood (Caesalpinia sappan) and is sourced from sustainable forests. |
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| Cellulose Fibre | Fibres derived from plants including cotton, flax (linen), rayon, bamboo, and tencel. |
| Chamomile | Used for centuries in herbal medicine, the Chamomile is also a good source of yellows and greens in natural dyeing. |
| Chrome Mordant | Chrome Mordant (Potassium Dichromate) widely used as a mordant and to modify colours during the industrial revolution and in recent history. Now considered too toxic to warrant continued use in domestic conditions. It is available for use in teaching and industrial dye plants under professional supervision. It brightens the dye colour |
| Citric Acid | Citric Acid is a weak organic acid used as an acidifier to lower the pH in dyeing, and for setting the colours from Acid dyes |
| Cochineal | The source of the colour Carmine (also called Crimson Lake). The cactus munching Cochineal scale insect has been carefully harvested, dried and crushed to extract the desirable red dye colour for over a thousand years. It takes 70,000 insects to make just under half a kilogram of the precious natural dye. |
| Colourfast | Colourfastness indicates a dyes resistance to fading when washed or exposed to sunlight, general wear and tear, and substances such as perspiration; plus the transfer of colour when wet. See also Lightfastness. |
| Colour Theory | Understanding a little about colour and colour mixing provides the dyer with the tools to produce almost any colour from just the primary colours and a toner (black) i.e. yellow and blue dye will produce green. |
| Copper Mordant | Copper Sulphate Pentahydrate. Copper mordant links chemically with the fibre and creates attachment points which bond with the colourant from natural dyes creating light and wash fast colours. It can be used as a modifier to shift colours towards blue (depending on the natural dye used) to shades of green through to purple khaki, olive, bronze and brown. |
| Cream of Tartar | Cream of Tartar is used to soften fibre, to act as a buffer to maintain a slightly acidic dye bath, to help disperse the Natural Dye colour evenly and to brighten colours (i.e. taking cochineal to a true red) on wool, silk and other protein fibres. It is an optional addition to the Alum mordant solution at 3-5g per litre of water. |
| Cutch | Cutch (Catacheu) is derived from Acacia trees and contains tannins. It is a substantive natural dye (does not need a mordant to bind to the fibre). When used on its own, it achieves shades of grey-brown. After soaking in a dilute solution of ferrous sulphate (Iron mordant), known as saddening, it will produce dark shades of brown to black and a khaki brown with Copper mordant. An orange tone can be achieved when Titanium Oxalate is used as the after-soak. |
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| Direct Dyes | Direct dyes are also known as Substantive. The dyes do not need chemicals to make them bond with the fibre. They give good full colour on cellulose fibre but are far less effective on protein fibre and synthetics. Direct dyes do not have good washfastness |
| Discharge Dyes | Used in discharge paste to simultaneously remove colour from dyed fabric and replace it with the dye colour in the discharge paste. |
| Disperse Dyes | Dyes formulated for high temperature dyeing of polyester, other synthetics and plastics. |
| Dyes | Dyes are any substance that chemically bonds with fibre to impart colour. The difference between a dye and a paint (pigment) is that dye molecules are soluble in solution and become part of the fibre while pigments are insoluble and attach only to the surface of the fibre. Different types of dye are required for different materials and some dyes require additional chemicals to make the bond washfast and lightfast. |
| Dyebath | A container holding the solution in which dyes are dispersed ready for dyeing textiles. |
| Dyers Green Weed | Genista tinctoria (also known as Dyer’s Broom). A mixture of dried flowers and leaves which produces shades of yellow in natural dyeing. |
| Dyestuff | Dyestuff is any substance, natural or synthetic, used to extract colour for dyeing. Not all dyes are the same; different types of dye are suitable for different materials. i.e. Acid dyes are best for protein fibres while Procion MX perform best on cellulose fibres. |
| Elderberries | The fruit of the Elderberry, Sambucus nigra, yields shades of grey, pink and purple when used as a natural dye. It has poor lightfastness. |
| Exhaust | When the dye exhausts it means that it has all been absorbed by the fibre and will not give any further colour. |
| Extract | To draw out colour from dyestuff into solution. |
| Fibre Reactive Dyes | Same as Procion MX and other reactive dyes. See Procion MX Dyes |
| Fixitol P | Fixitol P (Retayne) improves dyefastness of direct and fibre reactive dyes by bonding to the dye molecule, increasing its size and making it less mobile. |
| Fugitive | Fugitive colours are prone to fading when exposed to sunlight (fugitive to light) or washing, as opposed to colourfast. |
| Fustic | A natural dye and source of tannin from the Fustic Tree (Chlorophora tinctoria), which is part of the Mulberry family, used to produce shades of yellow. |
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| Gall Nut | Gall nut (or Oak Gall) natural dye is made from oak apples or galls and a rich source of tannins. As a substantive dye it achieved shades of cream-grey. The nuts are powdered and added to a dilute solution of ferrous sulphate (Iron mordant) it will produce dark shades of traditional brown to black inks. Orange can be achieved when Titanium Oxalate is used as the after-soak. |
| Gram (gm/g) | Metric measurement of weight. There are 1000g in 1 kilogram. |
| Heather Flowers | Use dried heather flowers as a natural dye to produce yellows and greens. |
| Henna | Henna powder is from the flowering plant Lawsonia inermis, found in Africa, southern Asia and northern Australasia. It can be used as a temporary dye for both skin and hair but is also useful as a natural dye for colouring textiles to shades of brown, and oranges in an acidic dyebath. Henna is also a source of tannin. It is also used in indigo vats as the reducing agent. |
| Ice Dyeing | A technique of applying Procion MX dye over ice cubes placed on a bundle of cloth. As the ice melts the dye travels into the bundle and creates random patterning on the fabric. |
| Indigo |  Natural Indigo is obtained from plants (Indigofera tinctoria) which contain the indican molecule. The dye pre-cursor is extracted by soaking and then converted to the insoluble indigo in the extraction bath by vigorous stirring and finally precipitated for collection.
The naturally occurring indigo is impure and contains around 50% of indigo. Industrially produced, synthetic indigo, contains around 99% of indigo and is chemically indistinguishable from the plant derived material. The indigo molecule does not produce its blue colour until it is oxidised. The dye powder is dissolved in an alkali bath with the combined oxygen removed by adding Thiourea Dioxide to the indigo vat. The reduced leuco-indigo produced is only soluble in an alkaline solution made by dissolving sodium carbonate or caustic soda in water. The resultant solution is a yellow-green in colour. After immersing and soaking the wetted fibre, it is slowly lifted out to turn blue as it absorbs oxygen from the air. Subsequent dips are required to build up the familiar deep indigo blue colour. |
| Iron Mordant | Iron Mordant (Ferrous Sulphate Heptahydrate) links chemically with the fibre and creates attachment points which bond with the colourant from natural dyes creating light and washfast colours. It can be used as an after wash modifier to alter the colour obtained from dye plants (depending on the plant used) darkening the colour, known as ‘saddening’, yellows towards green, reds to brown and purples to black. |
| Ivy Leaves | Natural dyeing with dried ivy leaf produces shades of green. |
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| Jar Dyeing / Solar Dyeing | A method of sealing mordanted, undyed yarn in a water along with the dyestuff in a jar and placing it in the sunshine to steep. The dye colour increases over time which may take up to 1 month. |
| Kilogram (kg) | Metric measurement of weight equivalent to 2.2lb (imperial pound). |
| Lichen Dyes | Lichens are a symbiotic relationship of two organisms; algae living within the filaments of a fungus. There are many 1000’s of species of lichen across the world and some species have been used as a dyestuff for thousands of years. Ochrolechia Tartarea (Cudbear) was used traditionally to dye yarn to a vivid purple. Different techniques are used to extract the colour from lichens which produce a substantive dye that does not require a mordant. |
| Lightfast | Lightfastness is a measure of how chemically stable a dyed material is when exposed to light. Many natural dyes, particularly those derived from fruits and vegetables have a low level of lightfastness (improved by the use of mordants) whereas a vat dye, such as Indigo has a relatively high degree of lighfastness. Lightfastness is rated on a scale of 1 to 8, 8 being the most fade-resistant. Used correctly, synthetic dyes generally have a high degree of lightfastness although levels will vary between colours. |
| Litre (l) | Metric measurement of fluid equivalent to 1.8 pints |
| Logwood | Logwood (Haematoxylum campechianum) natural dye from central America was much sought after in the 17th century for its ability to dye textiles shades of purple-grey through to black. |
| Low Immersion Dyeing |  A variety of techniques used to randomly dye fabric, yarn or fibre using just the solution from the fixative and applying dye in either powder form or by syringe from a stock solution. Also known as Random dyeing and Space dyeing. |
| Ludigol F | A resist salt which enhances and maintains the colour of Procion MX dye when steam setting. It helps to prevent the tendency for these fibre reactive dye colours to weaken due to the reducing action caused by heat. |
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| Madder | The roots of Madder (Rubia tinctoria) have been used for thousands of years to produce a colour range from red to purple depending on the method or mordant used. |
| Marigold Flowers | Dye with these dried flowers to produce shades of yellow through to green. |
| Millilitre (ml) | Metric measurement of weight. There are 1000ml in 1 litre. |
| Mineral Dyes | Examples of mineral pigments include Azurite (copper carbonate) which produces a blue pigment and Hematite (Ferric oxide) which stain fabric and can be light fast but not wash fast. |
| Modifier | Use modifiers after the initial dyeing process to shift colours in natural dyeing. There are different types of modifier; acid (i.e. vinegar, citric acid, Cream of Tartar) which alters the pH of the solution, alkaline (i.e. soda ash, baking powder) and metallic mordants (i.e. iron, copper, tin). Each modifier will alter the initial colour achieved during the dyeing process |
| Mordant | A mordant links chemically with the fibre and creates attachment points which bond with the colourant from natural dyes creating light and wash fast colours. Mordants are also used to set the colours from flowers and leaves during the process of Botanical Eco Printing.
The most commonly used mordants are Alum (Potassium Aluminium Sulphate), Copper (Copper Sulphate), Tin (Stannous Chloride), and Iron (Ferrous Sulphate). These are used in various combinations for mordanting wool, silk and other protein fibres. The process of mordanting cotton, linen and other cellulose fibre for natural dyeing is different in that the mordants do not bond with the fibre. Cellulose needs first to be soaked in a solution of tannin so that a mordant can attach itself to the tannin. Mordants are also used to shift or alter colours i.e. Copper can turn yellows into greens. |
| Natural Dye & Natural Dyeing |  Natural dyes are derived from plants, insects, minerals and lichens. Colour results from one type of dyestuff can vary greatly depending on the method of dyeing employed. Factors including the hardness of water, pH level of solutions, the mordanting process (see Mordant), the type of fibre (protein or cellulose) and the ratio of dyestuff to fibre will create different results. Natural dyeing is an experimental and creative process and results are improved by careful note-taking. |
| Natural Dye Extract | Colour extracted from natural dyestuff, dried out and then ground to powder to produce a concentrated natural dye colour. Mordants and modifiers are used to shift colours and to help make them wash and lightfast. |
| Oak Bark | The bark from the Oak tree provides an excellent source of a tannic acid (Quercitannic acid) and can achieve shades of orange, brown, grey and even black when treated with different mordants to modify the colour. This tannin can be used with alum to fix natural dye colours on cellulose fibre. |
| Ounce (oz) | Imperial measurement of weight equivalent to 28.35g. |
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| pH | The pH is a measure of the level of acidity in a solution. Ranging from 0-14 (7 being neutral) a pH of less than 7 indicates acidity. The difference in pH levels will affect the final colour of dyes, alongside other factors such as water temperature and hardness plus mordants used and the fibre type. Acidity levels can be tested with pH paper, and adding acids such as citric acid, Cream of Tartar or white vinegar to the dyebath will increase the acidity. Tap water will have a significant range of pH over time which can affect the resulting dye colour during this period. |
| Persian Berries | The fruit of the Avignon buckthorn, this substantive yellow dye can be modified with alum to produce green. It is grown in France. |
| PFD (Prepared For Dyeing) | Starches, sizing, finishes and optical whiteners will interfere with the absorption, and therefore the effectiveness of dye. Additionally, oils and dirt from handing materials, plus cosmetics, deodorants and body lotions will potentially act as a resist to repel dyes. PFD (Prepared for Dyeing) or Scouring is the process of removing these residues (usually in a solution of Synthrapol 5ml to 2-3 litres of water) and rinsing well before dyeing. |
| Pint (pt) | Imperial measurement of fluid equivalent to 568ml (0.568 litre) |
| Poplar Buds | A good source of yellows and browns, these buds from the Black Poplar Tree will produce different shades depending on the method of mordanting. |
| Pound (lb) | Imperial measurement of weight equivalent to 454g |
| Procion MX Dyes |  A type of fibre reactive dye used mainly for cellulose fibre (cottons and linens etc) but also effective on silk and wool. Procion MX dyes are also known as fibre reactive dyes because they form a permanent bond with the fibre molecule by forming a covalent bond. A covalent bond forms between two non-metallic atoms by sharing electrons, i.e. oxygen and hydrogen (both non-metallic) make water (H²O). Once a bond is formed, the dye molecule and fibre molecule become permanently joined. Soda ash is used to set the Procion MX in a cold water dye bath and this low dyeing temperature makes them ideal for use in Batik work because they do not melt the wax resist, and for tie-dye techniques. |
| Protein Fibre | Fibres derived from animals including wool, hair and silk, plus soybean protein fibre (SPF). |
| Random Dyeing | See Low Immersion Dyeing |
| Resist Dyeing |  A technique of creating designs on fabric using a resist to repel the dye and stop it being absorbed by the fibre. Different types of resist include melted Batik wax, gutta and potato dextrin.
Tie-dyeing and Shibori involve making a resist by tying off or stitching sections of cloth to prevent the dye from reaching them. |
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| Sadden | A term used to describe the darkening or toning down of dye colours i.e. iron mordant is used as a modifier to sadden natural dye colours when used as an after wash. |
| Safflower | The natural dye from these dried flowers produces shades of yellow through to red. |
| Scour | See PFD |
| St Johns Wort | St John’s Wort (Hypericum perforatum) will yield yellow through to brown when used as a natural dye. |
| Shibori / Tie-Dyeing | See Resist Dyeing |
| Shift | The process of altering or tinting dye colours by using a mordant, tannin, chemical, another dye or by adjusting the pH level. i.e. Cream of Tartar will help to brighten colours, encouraging a bright red from Cochineal. |
| Silk Painting | 
Usually with steam-fix silk dyes but also with silk paints and Acid dyes. Different techniques are used to decorate the silk fabric. |
| Soda Ash | Soda Ash (sodium carbonate) is used to help dissolve natural and synthetic indigo along with Thiourea Dioxide, and is a component of Discharge Paste at 1 part Soda Ash to 4 parts Thiourea Dioxide. It can also be used as an alternative to Potash to add alkalinity to a natural dyebath to modify colours, and is required for fixing the colours of Procion MX (Fibre Reactive) dyes. |
| Sodium Hexametaphosphate | Sodium Hexametaphosphate (Calgon PT powder) is used to soften water from hard water areas for improved colour uptake when dyeing. |
| Sodium Sulphate Anhydrous | A stronger alternative to Glauber’s Salt, Sodium Sulphate Anhydrous helps with the levelling of synthetic dyes to provide even coverage. |
| Space Dyeing | See Low Immersion Dyeing |
| Spectralite | A consumer name used for both Sodium Hydrosulphite and Thiourea Dioxide. These are fundamentaly different chemicals and it is therefore important that the exact chemical is identified before use. |
| Steam Setting | A method of setting dyes, especially Acid dyes, silk dyes, Natural Dyes and Plants in Botanical Printing, using the indirect heat produced by steam. Items are packaged in watertight wrappers and suspended above the boiling water. |
| Steep | A method of extracting colour from natural dyes by soaking in hot water for a period of time. |
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| Sticklac | Sticklac is a resin secreted by the insect Laccifer lacca. It contains a percentage of Lac dye which is used to colour textiles to shades of red as a natural dye. Shellac, which is used as a varnish, primer, food glaze, and adhesive, is also a product of sticklac. |
| Substantive Dyes | Substantive dyes are dyes that can produce colour without using a mordant to make them stick. These include the tannic acid from gall nuts, walnut leaves, turmeric, as well as alizarin reds from annatto, cochineal and safflower, indigo and the purple of some molluscs. Mordants can be used with these dyes to enhance or modify the colours (see Modifier). |
| Synthrapol | A mild non-ionic low temperature concentrated detergent used to prevent back staining by removing dye which has not combined with the fabric. Also used to scour materials prior to dyeing (PFD), and as a wetting agent to help materials absorb the dye colour. |
| Tannin |  A number of different tannins (or tannic acid) occur in the wood, roots, bark, leaves and fruit of many plants. Each gives a different colour ranging from yellow to deep brown. They are used in dyeing textiles, tanning leather and ink making. Tannins are also used as a presoak when dyeing cellulose; the tannin gives Alum, and other mordants, an attachment point to make natural dye colours fix to the fibre. |
| Tansy | The natural dye from Tansy gives yellows through to green. |
| Temperature | The temperature of water is important when using dyes. Some dyes, such as Procion MX dyes, will perform well in cold water, making them useful for resist techniques such as wax Batik. Natural dyes generally require to steep in very hot water to extract the colour. Dye recipes may give temperatures as Fahrenheit (°F) although Celsius (°C) is now used in the UK and the rest of Europe. The boiling point for water is 100°C (95°F) – this is the temperature that water must reach before reducing the heat to a simmer. |
| Thickeners | Thickeners are added to dyes in different ratios to allow for printing or painting. Manutex is an alginate based thickener made from Kelp (seaweed). Indalca PA3R is a Guar Gum based thickener and is used in strongly alkaline conditions such as for discharge printing or devore. |
| Thiourea Dioxide | Thiourea Dioxide is an active reducing agent which removes the oxygen from indigo when combined with Soda Ash in vat dyeing, is also used for discharge printing and general colour stripping on cellulose and protein fibres. |
| Tin Mordant | Tin (Stannous Chloride) is used as a premordant or as an after treatment to adjust natural dye colours. It tends to brighten colours, especially yellows, oranges and reds. Use only at a rate of 0.5-2% WOF as too much Tin will make fibres brittle (adding Cream of Tarter at 5-10% will help to soften the fibre). |
| Titanium Oxalate | Use as a mordant to produce orange from tannins and to modify colours of other natural dyes; particularly useful for modifying colours during the Botanical Printing process. |
| Turmeric | Turmeric produces a yellow as strong as the colour of the dye powder. Mordanting is recommended as the colour can be less washfast than other yellow dyes (although it has no problem staining hands, pots and work surfaces!). |
| Urea | Urea is a humectant that retains moisture and slows the drying process, allowing more time for acid dyes to react with fibre when printing, painting or applying it directly. |
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| Vat Dyes | Vat dyes are insoluble in water and and must be reduced The blue from Indigo is achieved through Vat dyeing. |
| Walnut Leaves / Husks | Use Walnut Leaves or husks as a source of tannin or extract the colour to produce a yellow through to brown natural dye. |
| Washfast | Washfastness is the level at which a dye colour is able to withstand fading or bleeding when washed. Washing at lower temperatures will help to prevent colour loss. Correctly applied synthetic dyes, especially Procion MX on cellulose, will give high washfastness. |
| Weld | Weld, Reseda luteola, (also known as Dyer’s Rocket and Dyer’s Mignonette) is a good source of yellows for natural dyers. |
| Woad | The yellow flowered Woad plant contains the same indigotin chemical produced by Indigo but at only 10% of the yield. Both dyes have been used for thousands of years to colour cloth to the familiar indigo blue. |
| WOF | WOF is an abbreviation for Percentage of the Weight of Fibre (or Fabric). Used in natural dye recipes to define the percentage weight of dyestuff or mordant required to dye fibre. i.e. Iron is used at 2-4% WOF and Madder is used at 35-100% WOF, depending on the depth of colour required. |
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