Gelatin sizing 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 is useful in photographic applications; we have found that gelatin-sized papers can withstand soaking and washing for hours at a time.