This is 1 lb of Arrowroot Starch from Photographers' Formulary. It is commonly used as a sizing when preparing papers for alternative process printing methods, such as cyanotypes and other hand-coated techniques. When mixed with water, and heated, this starch will form a paste that can be applied to papers in order to fill pores or other aberrations in order to produce a uniform surface for sensitizing.
UPC: 675152240033