Dichroic Coated Glass sheets are offered in 19″ inch diameter rounds. Depending on the glass manufacturer, the round sheets in most cases, have two flat sides approximately 16″ to 17″ inches apart. Approximate square inches of a “Full” 19″inch diameter sheet is: 283 square inches. Approximate square inches of a 19″ inch diameter sheet with flat sides is: 262 square inches. We also have the ability to coat 24″ inch diameter sheets (Please call us for details).