Note 47 — Chapter XXXIX

The Japanese paper, as well for writing and printing as for the household uses to which it is so extensively put, is manufactured from the bark of the young twigs of the paper mulberry (Morus papyrifira). Kämpfer has given a particular account of it in the appendix to his work. That account, which, now that so many experiments are on foot for the manufacture of paper, may suggest some useful hints, is abridged by Thunberg as follows:

“After the tree has shed its leaves in the month of December, they cut off the young shoots about three feet in length, which they tie up in bundles and boil in a lye of ashes, standing inverted in a copper kettle till the bark is so shrunk that half an inch of the woody part is seen bare at the ends. If the twigs grow dry before they can be boiled, they are first soaked in water for four-and-twenty hours. When sufficiently boiled, they are taken out and the bark cut lengthwise and stripped off. After being soaked in water for three hours, the exterior black skin and the green part beneath it is scraped off with a knife, and the bark is then sorted into qualities; that which is a full year’s growth makes the best paper, and the less mature an inferior quality. Thus prepared and sorted, it is again boiled in a clear lye, being perpetually stirred, and fresh lye supplied to make up for the evaporation; and this process is continued till the bark is dissolved, as it were, separating into flocks and fibres. It must then be washed,—a process requiring care and judgment, as, if not carried far enough, the paper will be coarse, and if too far, thin and slazy. This is done in a running stream, by means of a sieve containing the material, which is perpetually stirred till it is diluted into a delicate, soft pap. For the finer kinds this washing is repeated, a piece of linen being substituted for the sieve, to prevent the finer parts from being carried away. After being washed, it is beaten with sticks of hard wood, on a wooden table, till it is brought to a pulp, which if put into water will dissolve and disperse like meal.

“It is then mixed in a tub with a clammy infusion, obtained by soaking rice in cold water, and with another mucilaginous infusion, obtained in the like manner from the root of Oreni (Hibiscus manihot). This mixture, upon which much depends, and the proportions of which vary with the season of the year, succeeds best in a narrow tub, and requires perpetual stirring. The whole is then put into a larger tub, from which the sheets are taken out and put between mats made of delicate grass straw, and laid one upon another in heaps, being pressed at first lightly, but gradually harder and harder, till the water is squeezed out. They are then laid upon a board to dry in the sun; after which they are packed in bundles for sale and use.

“For the coarser kinds of paper other sorts of bark are sometimes used.

“The Japanese paper is very close and strong. It will bear being twisted into ropes, and is occasionally used even for dresses.”