Modular glass reference plate assembly

2 Systems, methods, and apparatus relate to a glass reference plate panel; to a modular glass reference plate assembly; and to creation of the modular glass reference plate assembly, which may include providing a plurality of glass reference plate panels, arranging the plurality of glass reference plate panels into an array of adjoining glass reference plate panels, and adhering together the adjoining glass reference plate panels. One or more embodiments may include 6.8 mm-thick borosilicate glass, ground, and polished, with reference marks on a top side and a PVD aluminum coating on a bottom side, perforated with holes, arranged in a 4×4 array of 16 glass reference plate panels, each approximately 810 mmin size, abutting at interfaces formed by lap joints, and bonded together with a UV-curable adhesive into a contiguous piece.