Oak Gall Extract > 95% 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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