In Meng Qian Bi Tan, the usage of clay type is described as follows:
The blank of the same specification is made of clay, and one end is engraved with reflexive characters. The height of a character is like the thickness of the edge of a copper coin, which has been tempered by fire. In order to meet the needs of typesetting, when repeated in the same version, there are usually several or even dozens of commonly used words for use. If you encounter uncommon words, you can use them with the system without prior preparation. In order to choose words conveniently, put glue. Write a note on it. When typesetting, the iron plate with frame is used as the backing, and a layer of medicine made of turpentine, wax and paper scraps is coated on it, and then the required clay movable type is sorted out and put into the frame one by one. When a frame is filled, it becomes a version, and then it is baked with fire. When the medicine melts slightly, the words are flattened with a flat plate, and after the medicine cools and solidifies, it becomes a version. When printing, as long as it is the last edition. Just increase the pressure. For continuous printing, two iron plates are used, one with a writing brush and the other with typesetting, and the two plates are used alternately. After printing, bake it with a torch, shake your hand gently, and the movable type can be separated from the iron plate, and then put it back in the original wooden lattice according to rhyme, and use it next time.
In Meng Qian Bi Tan, wooden movable type is described:
The reason why we don't use wood to make movable type dies is that the wood grain is uneven, and it will become uneven after being soaked in water, so it is easy to stick the medicine and it is impossible to remove the movable type dies.
From Shen Kuo's description of clay type and wood type in Meng Qian Bi Tan, we can see that:
Rubber movable type is simpler and more practical than wood movable type, which can not only save a lot of manpower and material resources, but also greatly improve the speed and quality of printing, so Bi Sheng chose rubber movable type instead of wood movable type at that time.
Unfortunately, movable type printing invented by Bi Sheng was not widely popularized and applied in China after his death. The earliest existing movable type printing is1103, which was unearthed from the White Elephant Tower in Wenzhou, Zhejiang Province in 1965, and was identified as Fuyuan to Chongning in the Northern Song Dynasty. However, the earliest existing wooden movable-type printed matter is19/kloc-0, which was unearthed from the square tower of Baisigou, Helan County, Ningxia Hui Autonomous Region in. In printing, the contents of this book include the large gap in the corner of the frame column line, the disjoint between the column line and the upper and lower column lines, the different strokes of the same word on the same side, the omission and omission of column lines and column lines, and the abbreviations and page numbers of ancient books.