Also known as oak gall, Aleppo gall, dyer’s gall, gallnut of commerce.

Unlike the usual powder, this is a highly concentrated extract of Quercus infectoria gall nuts. With a tannin content of over 95% gallotannins, it is one of the richest natural sources of tannin available. Gallnut extract has been used for centuries in both dyeing and ink making, prized for its ability to fix, deepen, and preserve colours.

Applied to textiles, oak gall nut extract enhances dye uptake, improves both light- and wash-fastness, and allows colours to age into more complex, layered tones. It is particularly important in “galling” cellulose fibres before mordanting with alum, ensuring long-lasting durability and brilliance.

Historical Note
Gallnuts have been central to dyeing since antiquity and are mentioned in countless medieval and early modern dye books. They were also a vital ingredient in iron gall ink, the standard writing ink of Europe for more than a thousand years. Their role in natural dyeing is equally enduring, forming the backbone of tannin-based mordanting for cellulose.

Active Dye Components

• Gallotannins (hydrolysable tannins, over 95%)

CI Colour Name
Not a dye in itself; classified as a tannin mordant/assist.

Advantages

• Increases lightfastness: protects colours from fading in sunlight
• Improves wash fastness: stabilises colours through repeated laundering
• Ideal for galling: strengthens mordanting on cellulose fibres
• Eco-friendly: sustainably sourced, biodegradable, and non-toxic

Shading Tips

• Alone → soft beiges to grey-browns (with iron modifiers, near-black)
• With alum mordant → clearer shades, better brilliance
• With iron → dark greys and near-black
• Essential as a tannin base for cotton, linen, and hemp mordanting

Light fastness: excellent (when used as a tannin base or with iron).

Source
Derived from sustainably harvested oak galls of Quercus infectoria.