Abstract: This disclosure teaches a screen such as those generally used for exhibiting projected images. A boxlike frame has a rim formed about its front. A membrane (the projection screen) covers the front with its margin extending to the vicinity of the rim. A cover encloses the back of the frame and is connected in sealed engagement to the margin of the membrane so as to form a plenum. Gas is withdrawn from the plenum whereby the membrane forms a concave image receiving surface curved in a relatively constant degree about a single point so that the image receiving surface takes on a spherical shape.