Alvin flexible 18" ruler is made of the finest-quality stainless steel with non-skid STA-PUT cork backing that won't slip on glass or polished surfaces. This ruled straightedge is flexible enough to permit measuring and marking on curved surfaces. Raised edges eliminate ink blots and smearing. Permanent acid-etched graduations won't wear off. Graduated to 32nds and 16ths and metric to permit close work. Great for school, shop, office, or studio.