Crepeline is a silk organdy that has a loose weave that is used extensively in textile conservation. For textiles that are in tatters, the pieces are laid on top of a sheet of crepeline and the textile is sewn onto the top. I've also seen it used in the Metropolitain Museum of Art in New York on Louis XVI silk embroidered chairs. The embroidery was so fine and the 18th-century silk so fragile that the entire fabric portions of the chairs (seats and backs) were covered in this gossamer stuff that wasn't even immediately noticeable up close. It's fantastic stuff, heaven sent, and just the thing for tattering samplers and silk tafetta skirts.