Our gelatin sizing is made from animal bone. It is a purely natural product, and was used as sizing for centuries in European and early American papers. It is a little more complicated to use than our regular "Carriage House Sizing", but it can result in special effects that are not possible otherwise. The gelatin may be used either as an internal or an external sizing, meaning that you can add it to the beater or the vat before making sheets of paper; or it may be brushed onto the dry, finished sheets. Gelatin also may prove useful in photographic applications; we have found that gelatin-sized papers can withstand soaking and washing for hours at a time. As with all our additives, instructions for use are included.