Size: Approximately 293 x 400mm Thickness: Approximately 3mm COE: 90 This glass sheet, with a coefficient of expansion (COE) of 90, is suitable for stained glass and fusing. It generally works well with Bullseye glass sheets, which also have a COE of 90. However, since we haven't tested all color combinations, we recommend pre-testing if you plan to fire them together. Notes: The thickness is more uniform compared to Bullseye glass sheets, so it can be used with relatively little waste. However, because it is not machine-rolled, there may be variations in air bubbles, thickness on one side, and width (approximately 28.5cm to 29.5cm) depending on the manufacturing period of the rods. This model number is for opaque black glass. It basically does not transmit light (see image). Please note that the color of the glass may vary slightly depending on the time of arrival.