天工開物·殺青（節選）天工开物·杀青（节选）

Master Song says: the essence of the images of things and the subtleties of heaven and earth are passed on from antiquity to the present and from China to other lands, so that those born later can take them in with their eyes and know them in their hearts. What is it that carries them? Rulers communicate with the people, teachers give instructions to their students; if they relied only on the chatter of spoken words, how far would they reach? But take a few inches of writing, hold half a scroll, and the purpose is explained from beginning to end, spreading like the wind and clearing doubts like melting ice. Everything between heaven and earth depends on Master Paper, and the wise and the dull alike are grateful for him. His body is made of bamboo and of bark. Kill the green, and the white appears; ten thousand scrolls and a hundred schools of thought are founded on this. Its finest use is here; its coarser uses are in keeping out the wind and wrapping things. The craft began in high antiquity. How narrow it was of the people of Han and Jin to claim the credit for it in their records.

Materials for Paper#

For paper, the bark of the paper mulberry tree (also called the gu tree), together with such things as mulberry inner bark and the bark of the cotton rose, makes bark paper; bamboo fibre makes bamboo paper. The fine grades are perfectly white and are used for writing, printing, letters and invitations; the coarse grades become paper for burning and wrapping paper. What is called "killing the green" takes its name from cutting bamboo; "sweating the green" takes its name from boiling and draining; and "jian", the word for a slip, was the name for finished paper, made by boiling bamboo into sheets. Later people came to suspect that it meant whittling slips of bamboo to keep records on, and wrongly supposed that the "leather binding" of the old books meant strips of leather threaded through bamboo slips. Before the burning of the books by the Qin, there were a great many books. How many could whittled bamboo have held? Likewise, in the western lands they make paper leaves from the pattra tree, and in China people suppose instead that the sutras were written on the tree's leaves. They do not know that a leaf withers as soon as it leaves its root. It is as laughable as the whittled bamboo.

Making Bamboo Paper#

The making of bamboo paper comes from the south, and Fujian province alone excels in it. After the shoots have grown, people look at how deep the hollows in the hills are; the best material is bamboo about to put out branches and leaves. Around the solar term Grain in Ear they climb the hills and cut the bamboo, cut it into lengths of five to seven feet, dig a pool right there on the hill, fill it with water and soak the bamboo in it. In case the water in the pool should dry up, they bring water through bamboo pipes, so that a stream flows in without stopping. After soaking for more than a hundred days, the bamboo is beaten and washed to remove the coarse husk and the green skin (this is what is called killing the green). The pulp inside looks like ramie. It is coated with a liquid of the best lime and put into a cooking tub, and boiled over a fire for eight days and eight nights as the rule.

For boiling the bamboo, the pan used is four feet across. Above the pan a rim is built up of clay mixed with lime, as high and wide as the salt-boiling pans of Guangdong, so that it can hold more than ten piculs of water. A cooking tub is set over it, fifteen feet around and more than four feet across. Once covered, it is boiled, and eight days is enough. After the fire has been stopped for a day, the cover is lifted and the bamboo fibre is taken out and washed clean in a rinsing pool of clear water. The bottom and four sides of this pool are all lined with close-fitting wooden boards, to keep out mud and dirt (this is not necessary for coarse paper). After washing, the fibre is soaked in a liquid of wood ash, put back into the pan, pressed level, and covered with about an inch of rice-straw ash. When the water in the tub boils, the fibre is taken out and put into another tub, and the ash liquid is poured over it again. If the water cools, it is reheated and poured over once more. After a dozen days or so of this, it rots and smells. It is then taken out and pounded in a mortar (in the hill country there are always water-driven trip-hammers) until it looks like dough, and then poured into a vat.

The vat for making paper is shaped like a square bushel measure. Its size depends on the mould, and the mould depends on the size of the paper. When the bamboo fibre is ready, clear water is added to about three inches above it, and a paper medicine is put in (made from a plant like the peach-bamboo leaf, which has no fixed name in the local speech), so that when the water is gone the paper will be clean and white. The paper mould is woven from very fine strips of bamboo, scraped and polished. When it is unrolled and spread out, there is a frame of cross bars beneath it. Holding the mould in both hands, the maker dips it into the water and lifts up the bamboo fibre so that it settles on the mould. The thickness depends on the maker's hand: a light dip makes thin paper, a heavy dip makes thick paper. While the fibre floats on the mould, water drains away on all four sides back into the vat. Then the mould is turned over and the sheet laid down on a board, and the sheets are piled up in thousands. When the count is complete, a board is placed on top to press them, and a rope and a lever are used, as in pressing wine, until all the water has run out. Then, with fine light copper tweezers, the sheets are lifted one by one and dried over heat. For drying, a narrow double-walled passage is first built of clay bricks, with bricks laid over the floor of the passage; every few bricks, one is left out. The fire is lit at the mouth of the passage, and the heat comes through the gaps in the bricks, so that the outer bricks all become hot. The wet sheets are pasted on one by one to dry, then peeled off and gathered into bundles.

In recent times the wide sheets called Great Fourfold have been prized for writing. Waste paper can be washed clean of red and black ink and dirt, soaked until soft, put back into the vat and made again. This saves all the labour of boiling and soaking and still makes paper, with little loss. In the south, where bamboo is cheap, people do not bother. In the north, even scraps and corners picked up from the ground are made again, and this is called paper of the returning soul. Bamboo and bark, fine and coarse, are all made in the same way. For burning paper and rough paper, the cutting of the bamboo, the boiling of the fibre, the lime liquid and the pouring of water are all done in the same way as above, except that after the sheets are taken off the mould they are not dried over heat, but are pressed to remove the water and dried in the sun.