Abstract: An apparatus is provided for positioning a workpiece with high accuracy and repeatably positioning the workpiece with similar accuracy while avoiding further manual alignment operations. Tapered pins, movable axially against a spring, are used to support a registration frame above the workpiece and allow attachment of the registration frame to the workpiece with high accuracy after initial manual positioning of the workpiece. After attachment of the registration frame to the workpiece, the use of similar, spring-loaded, tapered pins assures accuracy of positioning without further manual alignment. The axial motion of the pins is particularly advantageous during alignment of a plurality of workpieces in stacks and for processes requiring two-sided registration. During the alignment operation, a vacuum block is relatively movable on a base block and a workpiece immobilized on the vacuum block by a vacuum selectively applied to a portion thereof.