Calcium hydroxide is used to make an indigo or woad vat more alkaline.  It is a fine white powder and is also known as pickling lime,
Calcium hydroxide is used in Michel Garcia’s 1-2-3 vat recipe, which we is used in our shibori kit.  It is a mild alkali and easier to use than lye or caustic soda.
We provide a food grade quality calcium hydroxide.  Please wear a mask when using it as it is very fine and can be an irritating dust.