Calcium Carbonate (Chalk)
pH Adjuster for Natural Dyeing & Indigo Vats
Calcium Carbonate is a gentle, natural alkaline pH modifier used in natural dyeing to create the right conditions for dye extraction, colour development, and indigo vat preparation. It helps raise the pH of dye baths in a slow, controlled way, making it ideal when a milder alkali is preferred over soda ash.
 Features
Fine powdered Calcium Carbonate (CaCO₃)
Gentle alkaline pH adjuster
Ideal for indigo vats and alkaline dye baths
Supports aluminium acetate mordanting for cellulose fibres
Suitable for cotton, linen, wool, silk, and paper dyeing
 
 Dyeing Uses
Raises pH gradually without harsh alkalinity
Used in indigo fermentation vats and natural vat systems
Essential in the aluminium acetate mordanting process for cellulose fibres, where calcium carbonate helps fix the aluminium to the fibre after the mordant bath
Helps shift some dyes toward warmer or brighter tones
Useful in lake pigment making and dye extraction
Suggested Use
Add small amounts gradually and test pH as you go
Dissolve in warm water before adding to dye baths or vats
For aluminium acetate mordanting: use as the calcium fix bath following the mordant step
 
 Safety Note
Avoid breathing dust and wear a mask when handling powders. For dye and craft use only — not for food use.