How was ancient printing printed?

Do you mean block printing or movable type printing?

Printing block

When printing books, first dip the brush into the ink and brush it on the engraving. Then, put a piece of white paper on the board and gently brush it on the back of the paper with a clean brush. Then, take off the paper and a page of the book will be printed. After printed page by page, bound into a book, a book will be successful. This printing method is printed by engraving on the wood board, so everyone calls it "block printing".

movable type

Bi Sheng's method is as follows: make a blank with the same specification with clay, carve a reflexive character at one end, the height of the character is as high as the thickness of the edge of the copper coin, and then harden it with fire to become a single clay movable type. In order to meet the needs of typesetting, there are usually several or even dozens of commonly used words available for reuse in the same version. If you encounter uncommon words, you can use the system if you are not prepared in advance. In order to facilitate the selection of characters, the clay type characters are put into the wooden lattice according to rhyme and marked with a note. When typesetting, an iron plate with a frame is used as the base, and a layer of medicine made of turpentine, wax and paper powder is coated on it, and then the required clay movable type is picked out one by one and arranged in the frame. When a frame is filled, it becomes a version, and then it is baked with fire. When the medicine melts slightly, flatten the words with a flat plate, and after the medicine cools and solidifies, it will be printed. When printing, just brush ink on the board, cover it with paper, and apply some pressure. For continuous printing, two iron plates are used, one with a writing brush and the other with a typesetting board, and the two iron plates are used alternately. After printing, burn it with a torch, shake it gently with your hand, and the movable type will fall off the iron plate, and then put it back in the original wooden box according to the rhyme for next use.