Hardcover Book Cover: 157gsm art paper with 2mm greyboard ... calendar, company/products/advertisement adbrochure,instruction book,catalogue, card, magzine, hardcover book, softcover book, flyer, folder, sleeve, envelope, ... single white and grey or double white and inside grey.Duplex Board:From 250g to 450g, ... . 120g and 157g is normally used for book printing and envelope.cardboard paper:From 250g to ...