What type of lampshade gives the most light?

The lampshade that gives the most light is said to be bell shades. However, the luminance from a lampshade also depends on the room size, shape and purpose of the shade. Traditionally, white shades light up the entire room, whereas dark ones are used for making a vivid picture and are also preferred. On 1stDibs, find a collection of antique and vintage lampshades.