Moiré silk
This is an effect created during the finishing of the silk material called Calendering. This involves folding the silk material and passing it under rollers at high temperatures and pressures. The result is an attractive wavy, watermarked patterning to the silk.
Moiré Silk was sometimes used for the interior wall lining of boxes, jewellery tray lining, document book lining, and lining the insides of the concealed leather-bound letter wallets in the lid section of the box.