The traditional China engraved block printing technique requires the collaboration of half a dozen craftspeople possessed of printing expertise, dexterity and team spirit. The blocks themselves, made from the fine-grained wood of pear or jujube trees, are cut to a thickness of two centimetres and polished with sandpaper to prepare them for engraving. Drafts of the desired images are brushed onto extremely thin paper and scrutinized for errors before they are transferred onto blocks. The inked designs provide a guide for the artisan who cuts the picture or design into the wood, producing raised characters that will eventually apply ink to paper. First, though, the blocks are tested with red and then blue ink and corrections are made to the carving. Finally, when the block is ready to be used, it is covered with ink and pressed by hand onto paper to print the final image. Block engraving may be used to print books in a variety of traditional styles, to create modern books with conventional binding, or to reproduce ancient Chinese books. A number of printing workshops continue this handicraft today thanks to the knowledge and skills of the expert artisans.