Duplex Board 1,Sustances are from 250gsm to 550gsm. 2,Szies: Sheets and Reels. 3, A grade in quality 4, faster shipment 1, Sustances are from 250gsm to 550gsm.Szies:2, Sheets and Reels.Please ask us for detailed specifcation.3, Our quality is A grade. it is bigger amount qty we are exporting. carton boxes of Duplex Board with Grey Back