"IV E 9ab"--
Stamp affixed to portfolio.
Impressed mark on pages: "Tiroler Glasmalerei instalt in Innsbruck".
Plates are numbered and include design numbers. A previous owner has rearranged the plates and handwritten the "new" plate number in the bottom left corner of each plate, preceeded by either "XX" or "XIII".
Designs for decorative window panels (probably etched panels that imitate curtained windows).