Oak Gall – Natural Tannin for Cellulose Fibres

Quercus infectoria G.Olivier · Whole, Cut or Ground

Oak galls, also known as oak apples, are tannin-rich growths collected from the Aleppo oak in Turkey.

Exceptionally rich in light-coloured hydrolysable tannins, oak gall is particularly useful as the first stage of a two-step mordanting process for cotton, linen, hemp and other cellulose fibres.

Oak gall generally produces a light beige base colour. It introduces slightly more colour than Tara but considerably less than many darker tannin sources, making it a useful choice when preparing cellulose for pale or delicate natural dyes.

Choose whole galls for crushing, historical processes and long-term storage, cut galls for easier extraction and straining, or ground galls for the quickest and most thorough tannin release.

At a glance

What is an oak gall?

Oak galls are abnormal plant growths formed on the young twigs and branches of certain oak species in response to the activity of gall wasps.

The developing gall creates a protective structure around the insect larva. During its formation, the oak concentrates large quantities of tannins within the gall tissue.

The galls used for this product are collected from the Aleppo oak, Quercus infectoria, in Turkey. They are among the richest natural sources of hydrolysable tannins and have been traded for centuries for tanning, textile dyeing and ink making.

Despite the common name “oak apple,” the gall is not a fruit or acorn.

Oak gall as a tanning product

Aleppo oak galls are particularly rich in hydrolysable tannins, principally gallotannins.

Their tannin content is frequently reported at approximately 50–70%, although the precise amount varies according to the gall, maturity, collection, processing and storage.

Because oak gall contains a high proportion of comparatively pale tannins, only a relatively small quantity is required for cellulose preparation.

The resulting base colour is generally light beige. It is slightly more noticeable than Tara but remains considerably paler than many bark, fruit and leaf tannins.

Why cellulose fibres need two mordanting stages

Cotton, linen and other cellulose fibres do not naturally form a strong bond with aluminium mordants.

For this reason, our cellulose preparation uses two complementary stages:

1. A tannin treatment

2. A second mordanting treatment using alum with soda ash, aluminium acetate or aluminium lactate

The tannin stage and the aluminium stage work together. Tannin by itself does not complete the mordanting process, and the aluminium treatments are not sufficient by themselves either.

During the first stage, tannin is held by the cellulose fibre through affinity. It can still be removed if the fibre is rinsed aggressively or allowed to pass through an incomplete process.

During the second mordanting stage, the tannins are converted into insoluble tannates within the fibre. This creates the complete mordant system used to prepare the cellulose fibre for the subsequent dye.

Colour and its influence on the final shade

Oak gall produces a light beige base colour on cellulose fibres.

With pale, delicate or very clear dyes, this base colour may remain visible and gently warm the final shade.

With medium and strong dyes, its influence is usually subtle. This makes oak gall particularly useful where a high-tannin preparation is required without the stronger yellow or brown background associated with many other botanical tannins.

The final effect depends on:

• The amount of oak gall used

• The selected form

• Extraction time

• The fibre and its preparation

• The main dye colour

• Water chemistry

• The temperature of the tannin bath

• The second mordanting treatment

• Rinsing and finishing

Always prepare a sample when working towards a pale, bright or colour-sensitive result.

Choosing a form

Whole oak galls

• Suitable for historical processes, ink making and long-term storage

• Must be crushed or broken before textile extraction

• Require a longer soak than cut or ground material

• Easy to store with minimal dust

• Naturally vary in size, shape and colour

Cut oak galls

• Offer a larger surface area than whole galls

• Suitable for cold soaking and longer extractions

• Easier to strain than ground material

• Produce less sediment in the tannin bath

• Can be contained inside a cloth dye bag

Ground oak galls

• Provide the greatest surface area

• Release tannins more quickly and thoroughly

• Best for short cold extractions

• Produce more sediment than whole or cut material

• Should be made into a smooth paste before being added to the bath

• Require care to avoid creating airborne dust

The three forms are the same raw botanical material. Ground oak gall is not a concentrated extract.

How much to use

For general cellulose preparation, begin with:

10g oak gall per 100g dry fibre

Equivalent to 10% WOF - weight of dry fibre.

Whole galls must be crushed before use. Cut galls benefit from a longer cold soak, while ground galls release their tannins more readily.

Because oak gall is naturally very high in tannin, increasing the quantity is not always necessary. Excess material may deepen the beige base without improving the complete mordanting process.

These quantities are starting points. Natural tannin strength can vary between batches.

Suggested tannin treatment

1. Scour: Scour the cotton, linen or other cellulose fibre thoroughly to remove oils, waxes, sizing and processing residues.

2. Weigh: Weigh the dry fibre and calculate approximately 10% WOF oak gall.

3. Prepare the material: Crush whole galls thoroughly. Cut galls may be soaked before use. Mix ground galls into a smooth paste with a small amount of water.

4. Dilute: Add the prepared oak gall to enough cold water for the fibre to move freely and stir thoroughly.

5. Add the fibre: Add the thoroughly wetted cellulose fibre and ensure that it is completely immersed.

6. Treat: Keep the textile in a cold bath or at no more than approximately 30°C. Leave for at least 1–2 hours and up to 24 hours, moving the fibre occasionally.

7. Remove: Wearing gloves, remove the fibre and gently squeeze out the excess liquid.

8. Do not rinse: Tannin is held initially by affinity and can be removed by aggressive rinsing.

9. Do not dry: Proceed to the second mordanting stage while the fibre remains damp.

10. Second mordant: Complete the process with alum and soda ash, aluminium acetate or aluminium lactate, following the instructions for the chosen mordant.

11. Rinse: Once the second stage is complete, rinse the textile thoroughly to remove unattached mordant.

12. Dye: The textile may now be dyed immediately or dried and stored for future use.

Do not treat the oak gall bath as a complete mordanting process by itself. The second mordanting stage is essential.

Dyeing cotton, linen or another cellulose fibre? Find our complete cellulose mordanting guide here.

Choosing the second mordant

After the oak gall treatment, complete the mordanting process with one of the following:

Alum with soda ash

Our traditional two-stage method uses 12% WOF alum and 1.5% WOF soda ash after the tannin treatment.

The alum and soda ash solutions are prepared separately and then combined before the damp, tannin-treated textile is added.

Leave the textile in the second bath for a minimum of two hours and up to 24 hours. Rinse thoroughly after this stage.

Aluminium acetate

Aluminium acetate can be used as the second mordanting stage after the oak gall treatment.

Follow the appropriate quantity and method for the particular aluminium acetate product. A chalk afterbath may be required where specified by the recipe.

Aluminium lactate

Aluminium lactate is another option for the second stage of suitably prepared cellulose fibres.

Apply it after the oak gall treatment, following the correct quantities and safety guidance for the product.

Do not combine quantities or instructions from unrelated mordanting methods.

Tips from the dye pot

Using oak gall with iron

Oak gall reacts strongly with iron to produce grey, blue-grey, charcoal and black.

For a grey or black textile process, the tannin-treated fibre can be moved into a carefully measured iron bath without completing the alum stage. This is a different process from preparing cellulose for bright natural dye colours.

If iron is used as a modifier, begin with a very small quantity. Excessive iron can make colours harsh and may damage fibres over time.

The reaction between oak gall tannins and iron is also the basis of traditional iron-gall ink.

Iron-gall ink

Oak galls have been used for centuries in the preparation of iron-gall inks.

A concentrated oak gall extraction is combined with an iron salt, traditionally ferrous sulphate, to produce a dark iron-tannate colour. Gum arabic may then be added as a binder and to adjust the flow of the ink.

Iron-gall ink can be acidic or corrosive if poorly formulated. Use a researched recipe, measure all ingredients accurately and test the finished ink before applying it to valuable paper, textiles or artwork.

Tannin performance

Oak gall is used primarily to support the mordanting and subsequent dyeing of cellulose fibres rather than as a strong standalone dye.

The effectiveness of the complete preparation depends on:

• Thorough scouring

• Correct preparation of the chosen oak gall form

• Even tannin application

• Keeping the tannin bath cool

• Avoiding rinsing and drying between stages

• Completion of the second mordanting stage

• The chosen aluminium mordant

• The dye and dyeing method

• Water chemistry

• Rinsing, washing and aftercare

Oak gall’s light beige colour may remain visible beneath very pale dyes. With medium and deep colours, it generally provides a comparatively neutral tannin base.

Natural variation

Oak galls are insect-induced natural growths and vary considerably in size, form, colour and surface texture.

Whole galls may have natural holes where the mature gall wasp emerged. They may also contain small quantities of woody material or natural insect residue.

Colour can range from pale beige and grey-green to olive, brown or almost black. These differences are normal and do not necessarily indicate the strength of the tannin.

Particle size in cut and ground material may vary between batches. Tannin strength is also affected by maturity, harvesting, storage and processing.

Always sample before beginning an important or colour-sensitive project.

Storage and safe handling

• Store sealed in a cool, dry place away from direct sunlight.

• For textile dyeing, tanning, ink making, paper and craft use only.

• Not for consumption or use in food, drinks, cosmetics or herbal preparations.

• Avoid creating or breathing dust, particularly when handling ground oak gall.

• Work in a well-ventilated area.

• Wear suitable respiratory and eye protection when dusty material may become airborne.

• Avoid contact with the eyes, mouth and open wounds.

• Wear gloves where appropriate.

• Follow the safety instructions for alum, soda ash, aluminium acetate, aluminium lactate, iron salts and every other auxiliary used.

• Use dedicated dyeing and ink-making utensils—never food-preparation equipment.

• Keep away from food and out of reach of children and pets.

What you receive

Your chosen net weight of Turkish Aleppo oak galls in whole, cut or ground form, supplied in a sealed pouch.

Alum, soda ash, aluminium acetate, aluminium lactate, iron salts, dyes and other mordanting materials are sold separately.

Display jars, dyed textiles, inks and photographic props are not included.

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QUEBRACHO EXTRACT ~ Natural Tannin & Dye

Quebracho Extract, sourced from the bark of the Schinopsis tree, is a mild natural dye, rich in tannins. Traditionally used in textile dyeing, it enhances colour fixation on cellulose fibers, producing a range of warm, earthy hues from soft peach to reddish-brown. When combined with iron, it creates deeper, muted tones, making it perfect for creating nice, sustainable shades.

Uses & Benefits:

• Mordanting: Prepares cellulose fibers (ie. cotton, linen, hemp) for enhanced dye absorption.
• Dyeing: Produces vibrant peach, coral, terracotta, and red-brown hues, deepening when combined with iron.
• Versatile Applications: Ideal for textile arts, eco-conscious dyeing, and creating unique colour effects with natural mordants.

About the Plant:

Quebracho trees, native to South America, especially Argentina and Paraguay, are highly valued for their tannin-rich bark. Used for centuries in leather tanning, traditional dyeing, and natural medicine, Quebracho has a rich history in sustainable practices.

Recommended Usage for Dyeing:

• For light tones: Use 5–10% of the weight of the fabric (WOF).
• For medium shades: Use 10–20% WOF.
• For deeper hues: Use 20–30% WOF.
• To create darker shades: Combine with iron (1–2% WOF) for deeper, muted colours.

Dissolve the extract in hot water before adding it to your dye bath for best results. For optimal colour retention and vibrancy, use Quebracho Extract as a pre-mordant or combine with other natural mordants.

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Sumac Gallnut Extract
Source: Chinese Sumac Gallnut (Rhus semialata Murr.)

Sumac Gallnut Extract is a natural extract derived from the Chinese sumac gallnut, specifically developed for textile and natural dyeing applications. With a high tannic acid content and very low colour, this extract is ideal for pre-treating fibers and enhancing dye fixation.

Main Constituents:

• Hydrolysable Tannins (> 95%)
  
• Very low dust production during handling
• Highly soluble in both cold and hot water

Suggested Quantities (WOF - Weight of Fabric):

• Mordanting: Use 5–10% of fabric weight (WOF).
• For Darker Shades: Combine with iron sulphate (1–3% WOF) for deeper, darker tones.

Uses:

• Pre-treatment of Vegetable Fibres: This extract’s high tannic acid content is perfect for pre-treating cellulosic fibres to improve the fixation of mordants during the mordanting step.
• Natural Dyeing & Textile Printing: Any fibre can be dyed with Sumac Gallnut Extract. It enhances the lightfastness of resulting colours. When combined with iron sulphate, it forms dark, solid complexes that are perfect for shading darker shades (e.g. madder, indigo) on silk and wool, while reducing the risk of weakening fibres.
• Other Uses: Used in tannery processes and the manufacture of iron gall inks.

The Plant:
The Chinese sumac is a shrub ranging from 2 to 10m tall, native to northeastern India, China, Japan, Korea, and Indonesia. The galls are caused by the sting of an insect, usually a kind of wasp, on the leaves or bud. Sumac gallnuts are rich in hydrolysable tannins, particularly tannic acid.

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Oak Gall Extract > 50-60% tannic acid

Source: Oak Galls (Quercus infectoria, Quercus spp.)

Oak Gall Extract is a tannin-rich, natural auxiliary derived from galls formed on oak trees. These galls are exceptionally high in hydrolysable tannins, especially gallotannins, making this extract a powerful resource for natural dyeing, ink making, and cellulose fibre pretreatment.

Unlike condensed tannins (like those from acacia or quebracho), hydrolysable tannins such as these produce much cooler tones when combined with iron – ideal for grey colours and part of black colour development.

Main Components:

• Gallotannins (hydrolysable tannins)
• Gallic acid
• Ellagic acid

Suggested Quantities (WOF – Weight of Fabric):

• Pre-treatment: 10–15% WOF
• Iron dyeing (greys/blacks): 15–20% WOF
• Ink making: 1 part oak gall extract to 1 part ferrous sulfate in water

Uses:

• Pre-treating Cellulose Fibres: Enhances mordanting and dye uptake
• Grey Dyeing with Iron: Creates cool to purple greys
• Ink Making: Core ingredient in historic iron gall inks
• Surface Design & Printing: Use in thickened pastes with iron modifiers

The Plant:

Oak galls form as a natural defence mechanism when certain wasps interact with oak trees. Rich in natural tannins, these galls have been harvested for centuries for dyeing and writing inks. This extract is purified and powdered for convenience and consistent performance.

Light Fastness:

High (when paired with a mordant)

Note:

This is not a dye extract with colour of its own, but a tannin auxiliary that works best when paired with metal salts (especially iron) or mordants.

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Quebracho Bark Natural Dye and Coloured Tannin

Schinopsis lorentzii · Cut or Ground · Condensed Tannin-Rich Bark

Quebracho bark produces soft pink-beige, warm tan, taupe, earthy brown and iron-grey shades.

Quebracho Colorado, Schinopsis lorentzii, is a dense South American hardwood traditionally valued for its condensed tannins. These tannins give the material a strong affinity with natural fibres and make it useful both as a natural dye and as a coloured tannin treatment for cellulose.

Choose cut bark for slower decoctions and easy straining or ground bark for greater contact with the extraction water and quicker tannin release.

For a faster-dissolving, standardised and considerably more concentrated product, choose our powdered Quebracho extract.

At a glance

• Botanical name: Schinopsis lorentzii

• Common name: Quebracho Colorado

• Plant part: Bark

• Available forms: Cut or ground

• Material: Raw botanical dye material—not an extract

• Main components: Condensed tannins, also known as proanthocyanidins

• Tannin type: Predominantly profisetinidins formed from catechin and fisetinidol units

• Natural colours: Pink-beige, warm tan, taupe and earthy brown

• With iron: Grey, charcoal-grey, grey-brown and deeper brown

• Fibres: Wool, silk, cotton and linen

• Suggested quantity: Approximately 30–50% WOF as a starting point

• Mordant: Recommended when used as a dye; may also be used as a coloured tannin treatment

• Colourfastness: Variable; poor to medium untreated, with improved results possible through suitable mordanting

• Suitable for vegan projects: Yes

Choosing a form

Cut Quebracho bark

• Coarse pieces suitable for soaking and slow extraction

• Easy to contain and strain

• May be extracted more than once

• Useful for longer, traditional decoctions

Ground Quebracho bark

• Greater surface contact with the extraction water

• Releases colour and tannin more readily

• Produces more sediment

• Best contained inside a fine cloth or dye bag

• Requires additional care to prevent airborne dust

How much to use

As a starting point, use:

30–50g Quebracho bark per 100g dry fibre

Equivalent to 30–50% WOF - weight of dry fibre.

Use the lower quantity for pale beige and tan shades. Increase the quantity or repeat the extraction for deeper colour or a stronger tannin treatment.

Because this is raw bark rather than a standardised extract, tannin and colour strength may vary. Deeper results may require up to 100% WOF.

The separate powdered extract is considerably more concentrated and should be used at a lower percentage.

Basic dyeing guide

1. Prepare: Scour the fibre thoroughly. Mordant using a suitable method where required, then wet the fibre.

2. Soak: Cover the Quebracho bark with water and leave it to soak overnight.

3. Extract: Heat the bark and soaking liquid at approximately 85–90°C for one hour. Cut bark may benefit from a longer or repeated extraction.

4. Strain: Strain the liquid through a cloth. Ground bark is best contained inside a fine dye bag.

5. Dye: Add the prepared fibre and hold the bath at approximately 80–85°C for one hour.

6. Deepen: Allow the fibre to cool in the bath. Leave it overnight where a deeper result is desired.

7. Finish: Remove the fibre, rinse thoroughly and wash gently.

Dyeing cotton, linen or another cellulose fibre? Find a suitable mordanting method here.

A coloured tannin for cellulose

Quebracho bark may be used as a tannin-rich preparation for cotton, linen and other cellulose fibres before an appropriate mordant or another dye is applied.

Unlike pale tannins, Quebracho contributes its own pink-beige, tan or brown colour. This underlying colour can influence subsequent dye layers.

Raw bark is not standardised like a commercial extract. Sample before using it as the tannin stage of an important project.

The powdered Quebracho extract is better suited where a measured, concentrated and readily soluble tannin source is required.

Colour shifts with iron

Iron reacts strongly with Quebracho tannins, shifting pink-beige and brown shades towards grey, charcoal-grey, grey-brown and deeper earthy tones.

Use iron sparingly. Approximately 1–3% WOF is generally sufficient when testing these shifts.

We prefer iron acetate where possible because it is gentler on fibres than ferrous sulphate. Excessive iron may make protein fibres feel harsh and contribute to fibre damage over time.

Iron can improve the fastness of some Quebracho shades, but performance still depends on the fibre, mordanting method and overall process.

Iron and other modifiers are sold separately.

Inks and surface colour

Concentrated Quebracho liquid can be explored for ink making, paper colouring and surface-design work.

Its condensed tannins react readily with iron to produce darker greys and browns. A suitable binder or complete ink recipe is required for durable surface application.

Filter ground-bark liquids carefully where a smooth finish is required.

Tips from the dye pot

Colourfastness

Quebracho’s colourfastness varies according to the fibre, mordant, depth of shade and application method.

Untreated shades may have poor to medium lightfastness. Suitable mordanting - particularly careful use of iron - can improve lightfastness and wash resistance, but every method should be sampled and tested.

Rubbing fastness is often better than resistance to fading.

Storage and safe handling

• Store tightly sealed in a cool, dry place away from direct sunlight.

• For textile dyeing, paper dyeing and craft use only.

• Not for consumption or use in food, drinks, cosmetics or herbal preparations.

• Avoid creating or breathing dust, particularly when handling ground bark.

• Prevent contact with the eyes, mouth and open wounds.

• Quebracho is highly astringent and may irritate the skin, eyes or respiratory system in susceptible individuals.

• Wear gloves and suitable protective equipment when handling dusty material.

• Follow the safety instructions for every mordant and modifier used.

• Use iron sparingly; excessive iron can damage fibres.

• Use dedicated dyeing utensils and containers - never food-preparation equipment.

• Keep away from food and out of reach of children and pets.

• For textile dyeing, paper dyeing and craft use only - not for consumption.

What you receive

Your chosen net weight of cut or ground Quebracho bark, supplied in a pouch.

Select the required form and pack size from the available options.

Powdered Quebracho extract, mordants, iron and other dyeing supplies are sold separately.

Packaging

We pack as sustainably as we can while protecting your dye materials. Pouch types may vary according to pack size and the availability of our preferred lower-impact options.

Display jars and other photographic props are not included.

Learn with us

Join The Natural Dyers & Growers Academy to share your results and explore natural colour alongside fellow dyers and dye-plant growers.

Mordanting is recommended.

Grape Seed Extract
Source: White Grape Seeds (Vitis Vinifera L.) | Grape Seed Extract from Occitania

Grape Seed Extract is a 100% natural dye made from the seeds of white grapes, upcycled from the by-products of the wine-making industry. Produced sustainably through a water-based extraction process, this extract supports circular economy principles, offering an eco-friendly option for textile dyeing and beyond.

Main Components:

• Condensed Tannins > 70% (catechin equivalent)
• Eco-friendly, upcycled product
• Water-extracted for minimal environmental impact

Suggested Quantities (WOF - Weight of Fabric):

• Light Shades: Use 5–10% WOF for soft, pinky-beige hues (without mordant).
• Medium Shades: Use 10–15% WOF for more intense colour.
• Dark Shades: Use 5–20% WOF and combine with mordants such as iron for darker tones like grey.

Uses:

• Natural Dye & Textile Printing: Suitable for all types of fibres, whether mordanted or not. Typical shades depend on the recipe and mordant, including pinky-beige (no mordant), grey (with iron), and orange (with titanium). The extract is registered as "metal-free" and provides good lightfastness.
• Other Uses: Ideal for tannery processes, antioxidants, and more.

The Plant:
The vine (Vitis vinifera) is a woody, climbing plant, known for its long stems that can grow up to six metres. Its small flowers are greenish-white, and the fruits are grape clusters. Grapes have been cultivated for thousands of years in Europe, western Asia, and northern Africa. They are used for fresh eating, drying as raisins, or fermentation to produce wine.

Upcycling of By-products:
Grape Seed Extract is produced through the upcycling of wine industry by-products, contributing to circular economy practices. The wine industry offers a wealth of natural ingredients such as wines, juices, concentrates, and polyphenols, while minimizing waste through innovation and new technologies. The producer is located in the heart of the South of France’s vineyard region and proudly contributes to this sustainable bio-economy.

Recipe for Dyeing with Grape Seed Extract:

Ingredients:

• Grape Seed Extract (use WOF formula)
• 1 litre of water to dissolve (adjust based on the amount of fabric)
• Pre-mordanted fabric (cotton, wool, silk)
• Optional: Iron modifier for grey tones

Instructions:

1. Dissolve the Grape Seed Extract in warm water, stirring well until fully dissolved.
2. Add pre-mordanted or not mordanted fabric to the dye bath.
3. Heat the fabric in the dye bath for 45–60 minutes, stirring occasionally, leave overnight (optional).
   
4. Rinse thoroughly in cold water and dry in the shade.
5. Optional: For grey tones, dip the dyed fabric in an iron modifier bath.

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