Abstract: A substrate cassette having a conventional form, an open container having an upper entrance and a narrow lower opening formed by two side panels and two end panels. A preferred embodiment includes a train of substrate alignment channels on the inner surfaces of the two side panels, each channel is U shaped and having planar surface with a left surface, a right surface, and a bottom surface. An arcuate curbing member disposed on a left surface in each of the substrate alignment channels. The arcuate curbing member includes a top end with a thinner sloped profile facing the upper open entrance of the cassette allowing a substrate to slide through and under a stepped lower end.