All of the pamphlets and tracts that Crouch collected were printed on paper. The boards of the bindings are constructed out of paper that is layered together, and twisted rolls of paper are used as the cores of the endbands. Paper plays an important role in the repair of the volumes too: from fixing tears, to reinforcing board attachments.
Paper is constructed from plant fibres that are beaten to a pulp and suspended in water before being pressed and dried. The source of fibres and technique of production are major factors in the quality and character of the final material. There was no paper making machine in the 17th century, so all of the paper in the Crouch volumes would have been made by hand, using a mould and deckle. The quality of paper between the items varies, depending on its age and source.
Paper is also used extensively in conservation treatments. In particular, Japanese papers and tissues are prized for their long fibres, strength, and durability. Japan has a long history of traditional paper making, a process called ‘Washi’ that is protected by UNESCO intangible world heritage status.
The Japanese papers used in the conservation of the Crouch collection are machine made using kozo fibres. These come from the inner bark for the Paper Mulberry tree, native to Asia.
The Kozo fibres are long, thin and contain a very high molecular weight of cellulose: the primary component of paper. This makes the material strong, durable, and flexible.
The RK15 tissue used is 10gsm (grams per square metre) in weight, and is used primarily to repair tears in the textblock given its light weight and semi translucency.
The RK17 tissue is heavier at 19gsm, and is usually used in the Crouch collection for strengthening splits in the textblock or as a preliminary spine lining.
RK 32 and 36 are around 34 gsm in weight, and opaque in appearance. They take tone well, and are usually used as a thicker, stronger paper for joint repair.
By Nikki Tomkins