Brick is a CBS premium dichroic coating offered on reed thin glass COE 90. Brick fires to natural rainbow colors. 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 dichroic 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.