Abstract: A planar mirror having a reflective surface of unusually superior quality formed by a metallized thin-film reflective sheet material in a stretched condition over a unitary frame having a raised integral peripheral ridge extending in an endless path therearound. The metallized thin-film sheet material is secured to the peripheral marginal portion of the frame on the forward side thereof thereby maintaining the stretched condition of the film over the peripheral ridge in a manner which provides uniform tensioning about the periphery of the ridge. A unique apparatus and an improved method of producing such mirrors is also disclosed.