A form of tannin which can be used as an assistant when dyeing with natural dyes.
Tannins are found in leaves, wood, bark, tea and fruit. Tannic acid is used to mordant cellulose (cotton & linen) fibres and fabrics before using Alum to prepare the cellulose to bind chemically with the naturally occurring dyes in plant materials. This is because Alum does not react with cellulose fibres in the same way as it does with protein fibres. In Botanical Printing, the source of Tannins is from the leaves and some flowers with the Alum used in the substrate or blanket to complete the reactions.
It is often combined with Alum and Iron mordant to enhance colours or change their tone. Tannic acid can be used to produce tans and greys when used as a dye in its own right, or as a final rinse to neutralise fibres dyed using indigo. Oranges can be achieved from tannin when Titanium Oxalate is used as the after-soak. 100g bag
