This is a classic antique Schoolhouse shade, a popular choice for schools and commercial buildings from 1900 -1940. These simple, utilitarian shades were popular because of their clean lines and effective light diffusion. Mass produced beginning around the turn of the 20th-century, these ubiquitous shades became a staple in restaurants and homes after being decommissioned from commercial buildings. They are now a popular choice for kitchens and bathrooms in both residential and commercial buildings. This shade is made from white opal glass, a translucent or opaque glass that is prepared by adding impurities (as fluorine compounds) used especially for ornamental pressed glass and for diffusing light without serious loss of lighting efficiency. This is not a new shade, it is an antique shade salvaged from an old building.