Washi – Handmade paper

One of the pleasures of dealing in ukiyo-e is to handle hosho on a daily basis and it is a fact that paper making was already established and used for every imaginable purpose in China and Japan well before Guttenberg was printing the Bible on some of the first western handmade paper.

Hosho, used for printmaking, was manufactured in Echizen and a short- fibred variety of kozo called Nasu Kozo was used. Sumptuous hosho is found on many Harunubu prints and also surimono where a thicker paper was needed to better show off blind printing and where editions were small. Paper is discernably thinner on most Hiroshige sets. Besides kozo, Mitsumata and Gampi fibres were used for paper making but kozo was found to be the most suitable for print making coming from the mulberry family. The trees – in fact one year old sprouts from old stumps – were harvested in December, consequently paper making was an occupation that didn’t interfere with summer farming and the cold weather conditions were also better suited to making paper. The inner white bark of the kozo branches was used to make the bast and this was obtained by steaming the branches and stripping the black and green bark away. The fibre was then boiled in an alkali potash solution to remove the lignin and pectin leaving primarily cellulose fibre. Foreign particles were laboriously removed in cold water (not always successfully as they are found sometimes on 19th century landscapes) The fibre was then beaten or rather loosened to obtain the bast. A mould (su- made of hundreds of rounded bamboo splints woven together with silk threads) was lowered into the vat of bast plus water and a viscous solution of neri (roots from the tororo plant soaked and pounded) to aid formation . An occasional heavier splint gave strength to the mould and this is what is seen when paper is held to the light producing a thinner paper along these strengtheners. Lack of these can be an indication of a later facsimile when machine made paper was used.

For ukiyoe, and especially during the 19th century, a white clay was added to the stock in the vat to lighten the paper and this can cause white blotches to appear over time and are often seen on 19th century landscapes.

The couched paper formed on the su was rolled onto a stack of sheets and very delicately pressed so that the pile weeped. After pressing and parting, the sheets were brushed onto a smooth wooden surface for drying. This gives hosho two distinct sides which can be seen with the eye.

Although print sizes were to some degree determined by the size of the hosho sheets, the primary factor governing formats were the regular government edicts that limited size and thickness.