A vacuum ring is coupled to a vacuum source and utilized to de-air a laminated, electrically heated glass assembly having a cut-out portion adjacent the peripheral marginal edge of the laminae while the assembly is positioned within a pressurized and heated autoclave unit. The vacuum ring has a channel for receiving the edge of the glass assembly and the walls of the channel each have a single longitudinally extending groove approximately intermediate the edges of the wall. At least one of the walls is provided with a lip like extension disposed to cover the cut-out portion of the one of the laminae. The grooves interconnect with a vacuum source. The channel generally conforms to the outer edge of the glass assembly with or without applied vacuum or pressure, and the provision of grooved walls tends to enhance the sealing of the ring to the glass.