Japanese Papermaking

Japanese Papermaking

Yuki Ito

Introduction

Whenever I traveled my home countries and encountered Japanese traditional papers, washi, I was always fascinated with the extremely thin but very sophisticated, beautiful papers. Although crafrmanship of hand papermaking in Japan has a long history, as Timothy Barrett says in this book, Japanese Papermaking (1992), "the majority of young people in Japan and many older people have no idea about how washi is made nor do they come in contact with it in their daily lives" (15). This was true to me, and in fact, I had many contact with washi, such as in calligraphy classes through elementary schools to junior high school, and in paper shops in Japan, I always wondered how those washi had been actually made. When I was conducting research to decide my topic for this project for chemistry and art class, I found the Barrett book. This book motivated me to actually explore the Japanese papermaking through this project.

Therefore, the goal of this project was to experience and learn techniques and whole process of Japanese hand papermaking from collecting kozo, embarking, cooking and beating fibers, paper formation, couching and to drying. The two variables were primarily employed for this experiment: 1) the different strategies for couching and drying and 2) how the appearance of the papers is different when the kozo fibers were mixed with other fibers, more particularly, jeans cotton fibers and pine fibers.

Background

According to historical study of Japanese papermaking by Barrett (1992), papermaking was primarily the off-season winter work of Japanese farmers. When rice cultivation and harvest was over in the end of October, Japanese farmers harvested kozo and other formation aid plants, such as tororo aoi. Only enough kozo and formation aid plants were grown and harvested to last through the winter months for papermaking, and the farmers returned to farming as soon as spring came. Early Japanese papers were of exceptional quality due to cold working condition during winter, which kept the inner bark fiber from spoiling even slightly after preparation. Households concentrated on and became very skilled at making one or a few types of paper (11-12).

In the feudalism period, all farmers belonged to their regional lords, and their lives were strongly affected by the prestige and names of the lords. If poor-quality work was discovered, the responsible party might end up paying with the loss of one of his appendages or even his life. Therefore, papermakers went to a great deal of trouble to implement any specific requests from above. Those in power were in a position to initiate experimentation and gradually perfect the process. The top priority was to make paper with great quality, which the lord would appreciate (13). In that pre-modern period, fibers for papermaking were gently treated, and the papermakers never employed strong chemicals or machines. Cooking was always a long and gentle process in wood-ash lye over a wood fire. All cooked barks were entirely beaten by hand, preserving the natural character and length of the fiber in the finished sheet. The whole process was carried out patiently, carefully, gently, and slowly. The quality of the paper, rather than time or profit was the priority (14).

However, the situation drastically changed after the initiation of modern Western technology and capitalistic economy. The mass production of paper in the Western style started in the beginning of the 20^th century, and the Western style papers replaced traditional handmade Japanese paper. Although various handmade papers are still produced today, they are used for special purposes such as calligraphy, letter, envelopes, and shoji papers. Moreover, the washi production transformed to a year-round operation from seasonal one. For economical purposes, chemicals became employed. The cooked fiber is beaten by machines and sometimes mixed and cleaned by machines. Foreign fibers and wood pulp are commonly used to lower the proportion of expensive native fiber. The dominant priority has changed from quality to profit (14-16).

Regretting the decline of Japanese tradition of hand papermaking, Barrett decided to learn the methodology of Japanese traditional papermaking. He conducted intensive research from 1975 to 1977 in Japan, and acquired the techniques of Japanese traditional skill of paper making craft, being trained by Katsu Tadahiko who was an apprentice of National Living Treasure Abe Eishiro. After the two years, he came back to the U.S and became an expert of Japanese papermaking in the United States. He does not only cultivate many fibers for Japanese papermaking, such as kozo, gampi, and mitsumata, he has been actively initiating Japanese papermaking skills in the United States, through publications and lectures (Barrett, 1992: x).

Kozo is a mulberry of the family Moraceae. Two most common citations for kozo are Broussnetia kzainoki Seib. and Broussonetia papyrifera Vent. The former seems to be preferred specie for cultivation of papermaking fiber, although it is not as hard as the letter. Broussonetia papyrifera can occasionally be found growing wild in America, but its fiber is occasionally designed paper mulberry. Between 1950 and 1960, C. H. Dexter and Sons, Inc., a paper manufacturer in Windsor Locks, Connecticut, conducted extensive experiments on the cultivation of kozo in America. The research concluded that the coastal South Carolina and Georgia and north-central Florida are the areas best adapted to kozo cultivation in the United States because of reliable summer rainfall and less drastic temperature fluctuations during the winter. The optimum harvests occur five to eight years after planting and decrease thereafter. The normal harvesting period of kozo trees is in November and December (Barrett, 1992:22 & 136-139).

There are some distinct characteristics between the bark fibers, such as kozo, and rag or other wooden fibers. Through the eyepiece the long bast fibers look like buttered spaghetti, while cotton rag or wooden fibers look more like a pile of twigs. These features of the actual shape and surface of the bast fibers and their freedom from irregularity, though barely visible to the naked eye, are directly related to the special look and feel of the finished papers. Much of the warmth, suppleness, and luster of Japanese is a result of the nature of the fiber itself and nothing more (Barrett, 1992: 21). Although Alabama kozo has a shorter fiber and make a weaker sheet than Japanese kozo, the paper is still of good quality (House,).

Procedure

<Raw Materials, Tools Required>

Raw Materials and Chemicals

· White and green bark of Alabama kozo120g

· Baking soda (Na2CO3)24g

· Polyarcrylamide synthetic formation aid1/5 table spoon + 800ml water

· Blue jeans cotton fibers (15 minutes beaten) 250ml.

· Plain pine pulp (50 minutes beaten)100ml

Equipments

· Cooking vessel

· Mixing stick

· Press board

· Felts

· Vats

· Mould and deckle

· Su

· Large plastic buckets

· A small plastic container

· Drying board

· Drain basket

· Wooden hammer

<The Procedure of Japanese Hand Papermaking>

Timothy Barrett (1992) presents, in his book "Japanese Papermaking," a simplified and a traditional Japanese papermaking methods. Considering the time and financial constraints, I mostly employed the simplified one and follow his instruction.

Harvesting Alabama Kozo

I went to chop down Alabama kozo trees in South Pittsburgh, TN on April 13^th with Dr. Bordley although it was out of the harvest seasons. We chopped off branches whose outermost barks were green and brought them back to a chemistry laboratory in Sewanee.

On the same day, all of leaves and small branches were cut off and other large branches were cut down to appropriate sizes enough to fit into a plastic container. Then, the cut kozo trees were soaked in a bucket full of cold water for two days.

Embarking the Kozo Trees

While the wood core accounts for the bulk of kozo trees, only the inner bark yields the fiber which is essential for papermaking. On April 15^th, the outermost layer of green barks was shaved off with a knife and then, the inner green and white barks were stripped off. Be sure to work in the direction of the tree’s growth, from root end to upper extremes. After scraping, hang the bark to dry completely before storage, preferably outdoors in the sun and breeze.

Cooking the Fiber

At least 2 hours before start actually cooking the fibers, the dried fibers were soaked in Clear, cool water so that it would more readily react to the hot alkali solution at the cooking step. In general, the more water, and the fresher, cleaner, and colder the water used during soaking, the better the final quality of the paper becomes. However, because of time constraints, a bucketful of normal water was used in this experiment.

The cooking step should be done only immediately prior to papermaking. The quicker the fiber is made into paper after cooking, the fresher the final paper. kozo fibers were cooked in a 20 percent baking-soda solution (50g baking soda per 6 liters of water). When the water was almost boiling, the alkali (baking soda) was stirred in and the soaked fiber were added. The fibers are cooked in alkaline solution in order to dissolve non-fiberous materials as well as to separate out the fibers used in papermaking. The pot was covered and the fibers were cooked at steady gentle boil for 2 hours. Throughout this process, the fibers were stirred and turned in every 30 minutes. When the fibers were fully cooked until all strands were easily parted with and against the grains. According to Barrett, this cooking process is a very important step because many subsequent problems with fiber beating, formation quality, hardness or softness of the paper, and the like can be traced to cooking.

Beating the Fiber

The cooked fibers were thoroughly rinsed with fresh water alt the baking soda was removed. Although the baking soda is regarded as a gentle cooking agent, the alkali can leave residual potassium in the fiber, which is just as likely to cause premature oxidation of the cellulose as the sodium residue remaining after the cooking.

After the washing, most excess of water was squeezed from the fiber with hands. Using a wooden hammer, a pile of fibers was struck and the beating process was continued until the fiber became spread out. Then the beating was stopped and I folded the fiber mass in on top of itself from the front and back to the center. Turn the folded the cluster of fiber upside down on the beating surface, and begin the routine again. When several pinches of the beaten fibers were put and shook into water in a jar and no large strands or clumps remain, the fibers are beaten enough.

Mixing Formation Aid

At least one night before papermaking, mix the synthetic formation aid. To prepare the synthetic formation aid solution, 1/5 teaspoon of power formation aid was mixed with 800ml of water (the ratio of 1/4 teaspoon of formation aid per 1 liter of water). When mixing the powder, the powder was added slowly and stirred thoroughly so that each particle was encapsulated with water. If the power is introduced all at once, it would from a thick globular mass resistant to further dissolution. When all of the formation aid power was added, the solution was mixed in an erratic manner every 5minutes for the next 20 minutes in order to raise any heavier particles that had settled to the bottom. A uniform, stringy, clear solution, free of specks or visible inconsistencies would be the final result, and an ideal formation aid would transform the character of the water to distinctively slithery and ropy.

Mixing the Stock

Add beaten fiber to the vat. Mix the fiber, with the mixing stick, into the water until no larger clumps or strands are evident. Then, add 1 liters of the formation aid, and mix thoroughly into the water and fiber with the mixing stick by using a lively circular motion and reaching all four corners of the vat. Keep mixing the fiber dispersion becomes uniform (about 5 minutes).

Sheet Forming

Soak the su with mesh attached in a bucket filled with cold, fresh water. Arrange the wet su on top of the mould (sewn edge near, mesh side up). Add the deckle on top of the su, align its edges with the mould below, and grasp the entire assembly at the middle of the long side. Raise the mould until it is almost perpendicular to the water’s surface. Slide the near edge of the mould into the stock about 15 cm from the near side of the vat and in the same movement lower your hands and twist your wrists to scoop a charge (a load of stock) up and out of the vat. Continuing to twist your wrist, tip the mould forward to send the charge rushing across the su and off the far edge of the mould. Repeat a total of three times in immediate, but relaxed, succession. After three rapid charge and dumps (roughly 10 seconds’ elapsed time), immediately charge the mould in the same fashion but do not cast off any of the solution; rather, fall immediately into a rhythmic rolling of the stock, front to back (near edge to far edge), on the su. Before all the water drains from this fourth charge, recharge the mould again from the near edge.

When a suitable thickness is attained, quickly tilt the mould so the remaining solution flows to the far edge of the mould, and pour the excess off one of the far corners of the mould. Do not tip the mould past perpendicular (to horizontal plane of the vat stock), or you may see the new fragile sheet slide off the su and into the vat. Set the mould to drain. Carefully remove the deckle, and set it aside.

Couching

Pick the su up with the left hand at the middle of the near (sewn) edge and raise it from the mould. When the entire su is horizontal, smooth the backside of the su along the splints with the flat of the hands from the center out to create intimate contact with a dry paper on a felt. Once the su is smoothed, release the sheet by gently pressing the back of the su along the near edge of the paper beneath. Once the su is properly released along the near edge, draw the rest of the su away, leaving the paper smooth and unwrinkled on top of a dried paper on a felt. When the kozo paper was successfully couched on the paper, another sheet of dry paper was put on it. In order to dry the fiber-paper, it was softly palmed.

Drying the Sheets and Parting

When the kozo paper became dried enough, it was transferred to a drying board and left until it became completely dried. The dried papers were pealed from the boards.

Observations and Data

1) Harvesting Alabama kozo (April 13^th, 2001)

As Dr. Bordely said, some kozo trees were growing along a railroad in South Pittsburgh because many birds travel along the railroad carrying the seeds of the kozo trees. They were not very tall, and in fact the trees looked like bushes. We distinguished the kozo trees by the three-pronged shape of the leaves. Because it was in spring, the green color of new leaves was very beautiful. However, kozo was apparently out of best harvest season, and indeed the surface of outermost barks of the trees was green. So whether kozo paper could be formed with the material or not was unclear at that moment.

Time	Beating Time (Minutes)	Observation
10:30 a.m. (April 19^th)	0	The fibers were still in the shape of barks although the surface looked fuzzy (many fibrils). Their color was yellow, or brownish yellow.
11:00 a.m. (April 19^th)	30	More fibrils appeared on the surface of the barks. The fibers looked more condensed and pressed; yet the individual fibers started being separated apart. (Inter-fiber bonds became destroyed.) The color of the fibers became white, brownish yellow.

1:20-50 p.m. (April 23^rd)	60	The fibers were more beaten. Although some fibers slowly separated from each other, most fibers still remained being attached each other. Considering this data, I concluded that more cooking would be necessary.
1:50 pm-2: 20 pm		The fibers were cooked again with 20 % alkaline baking soda solution for 30 minutes.
2: 20 p.m. – 4:10 p.m.	170	After 3 hour of beating, the individual fibers finally completely separated apart, and beaten down to almost 1 cm. The beaten fine fibers stuck each other like clay, and the color turned to be white-yellow.

Kozo fibers before beating Moderately (40mins/ up) and throughly (3 hrs/ bottem)

beaten fibers

5) Making Formation Aid (April 23^rd and 24^th )

I had some trouble in making formation aid solution, so I conducted some experiments in this process.

Ratio of formation aid and water	How the formation aid was mixed with water	The appearance and texture of formation aid solution (after a night)
1 teaspoon of formation aid with 700 ml of water	All of the formation aid was added into the water once.	Numbers of spherical gelatinous clumps were formed and remained in the water. The solution was not stringy at all. It was a complete failure because the solution did exactly what Barrett did not want. Re-consulting the instruction of Barrett, the formation aid was added too much to insufficient amount of water. Also, the formation aid should not have mixed with water simultaneously.
1/5 teaspoon of formation aid and 800 ml of water	The formation aid was added into the water slowly and little by little. The solution was stirred frequently and thoroughly. After all of formation aid was added to water, the solution was stirred every 5 minutes for the next 30 minutes.	After 30 minutes stirring, the formation aid looked quite evenly distributed and dissolved. However, many small gelatinous clumps still remained. So I decided to filter the solution and squeezed the small clumps for 5 times. After this process, the solution became a little stringy. Thus, this formation aid solution was employed for papermaking immediately after this filtering and squeezing. (Formation aid solution A)
1/5 teaspoon of formation aid and 800 ml of water	Same as the formation aid solution A	Mostly the same as the formation aid solution A, but the solution was left for a night before papermaking. The formation aid solution in a beaker was covered with plastic wrap to avoid exposed to humid air. (Formation aid solution B)

6) Mixing Stock, Sheet Forming, Couching and Separating Papers (April 23^rd & 24^th)

<Pure Kozo-Fiber Papers>

	Formation aid used	Number(s) of dipping	Method of Couching	Observation in couching process and appearance of the paper in a wet stage	Easiness to pealing and appearance in a dry stage
1	A	3	Sheet was formed and couched as described in the procedure section. Simply transferred to a drying board.	It was hard to transfer the paper onto a drying board and in fact, extremely thin parts were torn off. However, the fibers were attached together through water and small particles of formation aid. It seemed that the paper would be formed if the gelatinous particles, would dry. The color of the sheet was ocher	It was a labor to peal the paper from a drying board, although this paper was relatively easy to be pealed off compared to kozo papers 2, 3, 4 and 5. In dry state, the globular particles of formation aid disappeared, but instead, the particles formed thin transparent layers, which kept fine, short fibers together. This was apparent especially when the backside of the paper was observed. The front surface of the paper was rough, and how numbers of fine fibers with different lengths and thickness was observable with naked eyes. The parts contains many fibers were harder than thin parts. The color of the fibers looked much whiter compared to yellowish color in the wet stage. (These descriptions of appearance of the paper are true of other kozo papers.)
2	A	2	The same as kozo paper 1.	The paper was so thin that couching and transferring the paper to a drying board were very difficult. Probably, the paper should be dipped more than 3 times. The paper appeared almost the same as kozo paper 1 except for that this paper looked contain fewer fibers than the 1.	Because this paper was so thin that the most part of the paper became torn apart through pealing. The connections between fibers were very fragile, and some fibers came off when I was observing them with my hands. Definitely, certain thickness of fibers seemed necessary to obtain a complete dry sheet of paper.
3	A	4	Mostly the same as the method for kozo paper 1, but the paper was drained and more dehydrated with a dried paper and a felt before transferring.	Probably because the sheet was more dried than it was supposed to be, it was very hard to transfer the sheet of paper to a drying board.	The paper was too thin to be pealed off. Even a part of paper was unable to be obtained.
4	A	5	Same couching method as the kozo paper 1, but the wet paper was left on a dry paper rather than being transferred to a dying board.	The paper looked good. It seemed that the sheet contained sufficient amount of fibers, and the sheet looked thick enough. There were so many gelatinous particles of formation aid between the fibers.	Although this paper was as thick as the kozo paper 1, a complete sheet of paper could not be obtained. It was very hard to remove the sheet from the dry paper, and it did not seem to be a good idea to leave a paper under the wet sheet of paper throughout drying process. Many fibers remained on the dry paper and thin parts were torn apart through pealing.
5	B	5	The same couching, transferring, and drying methods as kozo paper 1.	The fibers relatively evenly distributed, and thickness of fibers looked appropriate. As the formation aid A was employed, the fibers were attached with glabrous particles of formation aid B solution.	This was the best kozo paper which was made in this experiment. Almost a complete sheet of paper was obtained after pealing. Fibers seemed most evenly distributed, and the paper was very soft but appeared durable. Compared to the papers formed with formation aid A, this paper with Formation aid B was much easier to be pealed. It seemed to be a better idea to leave formation aid at least for a night before actual paper-forming.
6	B	3	The same couching, transferring methods. Yet, a su was placed in-between wet sheet of paper and a drying board.	Although the fibers looked evenly spread, the wet sheet was extremely thinner than kozo sheet 5. I was afraid the paper would be torn apart when it would be pealed off from the drying board.	Although the paper was extremely thin, the paper was very easily pealed against the expectation. It seemed a great idea to have left su under the wet paper in drying process. The paper was very soft, but fibers were attached very well that the paper appeared durable.
7	B	4	The same couching, and transferring styles as other papers, but thick threads were placed in-between wet sheet of paper and a drying board. (Threads on the right and left side of wet paper.)	Because of the thickness of the threads, it was very hard to transfer the papers to the drying board. The paper looked thicker than the kozo paper 6.	Leaving thick threads under a wet formed paper was not a good strategy. Threads were so attached to the fibers that they were hard to be removed. Moreover, even the threads came off, the lines of threads were remained on the surface of the paper.

<Kozo fibers mixed with Jeans-cotton Fibers>

250 ml of blue-jeans cotton fibers were mixed with kozo-fiber stock and papers were formed with the same method as pure kozo fiber papers. Two questions were explored:

How the two different fibers were mixed and would turn out in a sheet of paper.
Weather Japanese papermaking methodology would be effective for fibers other than fibers of mulberry trees.

Formation aid used

Number(s) of dipping

Method of Couching

Observation in couching process and appearance of the paper in a wet stage

Easiness to pealing and appearance in a dry stage

The same as kozo paper 1.

Couching and transferring were very easy. The kozo fibers irregularly spread, but the yellow color of the kozo fibers was very beautiful against the blue jeans fibers. But I wondered if the kozo fibers would keep the color throughout the drying process.

Although the thread strategy worked in this case, it was not necessary because the jeans-cotton-kozo papers were overall very easy to be pealed. Moreover, the shape of a thread remained on the dry paper.

The surface of this paper was rough, and clumps of jeans-cotton fibers were observable on the surface of the paper. The backside of the paper was very smooth. The interesting finding was that the kozo fibers kept its yellow color and the contrast of yellow against blue color of jeans-cotton fibers turned out very beautifully.

The same as kozo paper 1. However, the wet paper was transferred to a drying board with less draining and drying than jeans-kozo paper 1.

It was a little hard to transfer the wet paper because the paper was not as dehydrated as the jeans-kozo paper 1. Still containing sufficient amount of water, the paper looked very thick and the surface of the wet paper looked rough. However, the kozo fibers seemed distributed relatively even.

Again, the front surface of the paper was very rough and the clumps of jeans-cotton fibers were distinctive, observing with naked eyes. The contrast of kozo fibers and jeans fibers was so beautiful.

The same as kozo paper 7. In transferring process, three threads were inserted between the wet paper and a drying board.

The transferring process was not as difficult as it was for kozo-paper 7. The surface of paper looked rough, but paper was thinner the papers which had been made with 2 dips.

The surface of this paper is most smooth of all three jeans-kozo papers. The mesh pattern of su remained on the paper. Although this paper was very thin, it appeared very durable and beautiful.

Jeans and Kozo fibers in formationa aid solution

<Papers of mixed with kozo, blue-jeans, and plain cotton fibers>

100 ml of 50 minutes beaten cotton fiber were added to the fiber stock of jeans and kozo, and three papers were formed with the same Japanese papermaking methodology. The same questions as the blue-jeans-kozo papermaking were examined.

How the two different fibers were mixed and would turn out in a sheet of paper.
Weather Japanese papermaking methodology would be effective for fibers other than fibers of mulberry trees.

Formation aid used

Number(s) of dipping

Method of Couching

Observation in couching process and appearance of the paper in a wet stage

Easiness to pealing and appearance in a dry stage

The same methodology as kozo paper 1.

Because the pine pulps were beaten well, the drainage time of this paper was much longer than those of pure kozo and jeans-cotton-kozo papers. The interesting thing was that this pine-jeans-kozo paper was much thinner than jeans-kozo paper 3 although both of the papers were formed with 1 dip. The three different fibers were mixed well, and looked very beautiful. The kozo fibers were evenly spread out.

This type of paper was also very easy to be pealed. Kozo fibers did not lose the yellow color, while blue of jeans fibers looked weaker by mixed with white pine pulp. The contrast of yellow of kozo against blue (jeans fibers) and while (pine pulp) appeared very beautiful. The kozo-jeans-pine-pulp papers generally turned out thinner than other types of papers (kozo, jeans-kozo papers), but this type of paper also looked durable. The mesh pattern of su remained on the paper surface.

The same as above.

The paper looked a bit thicker than the kozo-jeans-pine paper 1. The surface of the paper looked rough. The kozo fibers were distributed well.

The surface of this paper is the roughest of all the three kozo-jeans-pine papers. This paper seemed to contain less clumps of pine pulp and jeans fibers than the first kozo-jeans-pine paper.

The same as above.

Although this paper was more dipped than other two papers, this paper looked very thin. This must be probably because the fibers were running out after forming numbers of papers. (With this pulling method, the amount of fiber is uncontrollable.) However, the surface of the paper appeared smoother than the other two papers.

Of all the three, the surface of this paper is the most smooth, and this paper is the thinnest. However, the paper seemed fairy strong, and very beautiful.

Time	Cooking Time (min)	Observation (appearance of fibers and solution) & Interpretation
10:20 a.m.	0	The fiber looked green and fresh. The solution looked clear.
10:50 a.m.	30	The fibers turned greenish yellow. The solution started becoming opaque, cloudy.
11: 20 a.m.	60	Fibers became much softer, and actually the brown rigid parts where the new branch would appear could be easily pealed off with hands. Color of most fibers remained yellow-green, but some turned yellow-brownish. The solution looked clear but brownish.
11: 50 a.m.	90	Nothing seemed to have changed since 11:20 am. However, more fibers seemed to have become brownish.
12: 30 p.m.	130	Color of the fibers did not change since 11:20 a.m. However, the surface of the fibers became fuzzy and so many fibrils appeared. Probably, inter-fiber bonds became loosened with cooking with alkaline solution. The water became completely clear, but brownish.