text:  The Ming dynasty had seen considerable advancement in the process of colour printing in China . At his studio , Hu <unk> experimented with various forms of woodblock printing , creating processes for producing multi @-@ coloured prints and embossed printed designs . As a result , he was able to produce some of China 's first printed publications in colour , using a block printing technique known as " assorted block printing " ( <unk> <unk> , <unk> ) . This system made use of multiple blocks , each carved with a different part of the final image and each bearing a different colour . It was a lengthy , painstaking process , requiring thirty to fifty engraved printing blocks and up to seventy <unk> and impressions to create a single image . Hu also employed a related form of multiple @-@ block printing called " set @-@ block printing " ( <unk> <unk> , <unk> ) , which had existed since the Yuan period some 200 years earlier but had only recently come into fashion again . He refined these block printing techniques by developing a process for wiping some of the ink off the blocks before printing ; this enabled him to achieve gradation and modulation of shades which were not previously possible . 
  