... AA A and B grade quality duplex board grey back. Suitable for any kind famous brand offset printer, for example HEIDELBERG, ROLAND ... and laminating results. AAA AA Grade: 230GSM-500GSM, suit for 8 colors high speed printing, excellent printing result, and ... printing, nice printing result, and nice stiffness. B Grade: 200GSM-600GSM, suit for 4 colors ordinary speed printing, fine printing result ...