Duplex board with white back 1.Super stiffness and coating 2.Suitable for 6 or above colors printing 3.High stiffness Duplex board with white backsubs: 250g/280g/300g/350g/400g/450g/500g quality: AA grade, A grade and B gradeQuality Introduction:1.High surface intensity suitable for any kind famous brand of high-speed 4/6/8 colors offset printer, for example HEIDELBERG,ROLAND, KBA, MITSUBISHI, ...