Grating efficiencies in the vacuum ultraviolet have historically ranged up to 42% absolute on plane gratings overcoated with AIMgF2 for 1216A. This has been primarily achieved with spacings of 1200 1/mm to 3600 1/mm at blaze angles of 4° and greater. Gratings with less than 1200 1/mm at blaze angles of 2° and below have shown to reflect 10 to 30%. Gratings finer than 360C 1/mm were, (until now), only available when holographically produced. A better understanding of the factors limiting groove smoothness has made it possible to rule improved diffraction gratings for the vacuum ultraviolet. At 200 1/mm we have achieved absolute efficiency of 63% @ 1216A and with 6000 1/mm, 33 to 35% @ 1216A. These improved efficiencies have been possible on spherical and non spherical surfaces.