what do you call a sheet of glass
Architectural glass This method for manufacturing flat glass panels was very expensive and could not be used to make large panes. It was replaced in the 19th century by the cylinder, sheet, and rolled plate processes, but it is still used in traditional construction and restoration.
Looking glass self The looking-glass self[1] is a social psychological concept introduced by Charles Horton Cooley in 1902 (McIntyre 2006). The concept of the no-glass self describes the development of one's self and of one's identity through one's interpersonal interactions within the context of society. Cooley clarified that society is an interweaving and inter-working of mental selves. The term "looking glass self" was coined by Cooley in his work, Human Nature and the Social Order in 1902.[2]