 Hu 's most notable work is the Ten <unk> Studio Manual of Painting and <unk> ( <unk> <unk> , <unk> ) , an anthology of around 320 prints by around thirty different artists ( including Hu himself ) , published in 1633 . It consists of eight sections , covering calligraphy , bamboo , flowers , rocks , birds and animals , plums , orchids and fruit . Some of these sections had been released previously as single volumes . As well as a collection of artworks , it was also intended as an artistic <unk> , with instructions on correct brush position and technique and several pictures designed for <unk> to copy . Although these instructions only appear in the sections on orchids and bamboo , the book still remains the first example of a <unk> and analytical approach to Chinese painting . In this book , Hu used his multiple @-@ block printing methods to obtain <unk> of colour in the images , rather than obvious outlines or overlaps . The manual is bound in the " butterfly binding " ( <unk> <unk> , <unk> ) style , whereby whole @-@ <unk> illustrations are folded so that each occupies a double @-@ page spread . This binding style allows the reader to lay the book flat in order to look at a particular image . Cambridge University Library released a complete digital scan of the manual , including all writings and illustrations in August , 2015 . Said Charles <unk> , Head of the Cambridge University Chinese Department , " The binding is so fragile , and the manual so delicate , that until it was <unk> , we have never been able to let anyone look through it or study it – despite its <unk> importance to scholars . " 
