Square 1 is a CBS premium dichroic coating offered on thin glass COE 90. Square 1 is the color of Rainbow 1 and each square measures 1/8 inch. This coating is offered on clear and black glass in a 4x4 inch square or a quarter sheet. There are approximately 66 square inches in a quarter sheet of glass. Please Note: All photos on black glass. This is a Rainbow 1 or 2 glass coating. This means the coating has one rainbow across a full 19" sheet of glass. When the sheet of glass is cut each piece is a different section of the rainbow.