This is the No. 644 Aladdin parchment shade. It dates to 1930 or 1931 and was designed to fit the 12 inch vase lamps or the Aladdin bird cage floor lamps. You can see the stitching that secures the top and bottom shade rings in this photo. As these shades age the paper becomes brittle and great care must be taken when handling them since the stitching actually perforates the shade at both the top and bottom edges. When the paper was new it was very strong, but as it ages there is a tendency for the shade to separate along the perforations caused by the stitching.