Also known as aluminium diacetate

Aluminium acetate is one of the most effective mordants for cellulose fibres such as cotton, linen, and hemp. It binds strongly to plant fibres, helping dyes adhere better and improving both wash and light fastness. It is often used in a two-step process with a tannin mordant to create bright, durable shades on cellulose, though it can also be used on its own.

Historical Note
The first recorded description of aluminium acetate mordanting comes from Claude-Louis Berthollet (1748–1822), a French chemist and dyer. In his 1791 work Éléments de l’art de la teinture, Berthollet described methods of preparing aluminium salts, including alumina combined with acetic acid, and their use in mordanting cloth. His observations helped shift natural dyeing into a more scientific practice during the late 18th century.

Active Component
Aluminium acetate (a crystalline salt of aluminium and acetic acid).

Advantages

• Excellent for cellulose fibres (cotton, linen, hemp, viscose, Tencel).
• Produces bright, clear colours, especially with yellows and reds.
• Stronger bonding than alum alone.
• DIY option: aluminium acetate can be made from scratch by reacting alum with washing soda and vinegar (acetic acid), but this crystalline product is far more reliable, consistent, and easy to use.

Safety Notes

• Always wear gloves and protective clothing.
• Avoid inhaling powders; wear a dust mask when handling.
• Can be irritating to skin and eyes — handle with care.

Source
Produced as a crystalline salt for professional dyeing applications.