Indigo Vat Tin For Wool
To 2 quarts of water add 1/4 lb. lime, and make hot. Then add 1 oz.
indigo pounded up with a little of the lime water; let it stand and
get warmer. Pound up 1/2 oz. tin, Stannous Chloride, in a little
lime water and add, together with 1/2 oz. zinc. Add more lime water or
tin according to the state of the vat. There should be a streaky scum
on the surface, and the water underneath clear with a green tinge.
Pearl ash can be used instead of lime.