Specific Aspects of the Phenomenon in Which the Printing Area Shrinks and Expands in Orthogonal Axes of Facsimile Editions : Establishing a Method to Distinguish Between Editions by Comparing the Distances Between Printed Page Borders : The literature notes a phenomenon in which the printing area shrinks when producing facsimile editions (created through a technique called kabuse-bori where the printed pages of an older edition are used as a basis for carving new wooden matrices, as opposed to a reproduction that uses new copy written by hand based on an older edition to carve new matrices), with an average shrinkage of 6 to 7 mm vertically for ōhon (“large-size books”). The present study examines this phenomenon by examining several editions of three texts : Makura-no-Sōshi Shunsho-shō, Zoku-Taiheiki Rishu-hen, and Sangō Shiki-chū (Kakumyō-chū). As a result, it was found that the editions of all texts display a near normal distribution, with the amounts of shrinkage showing a distribution in a range of about 0 to 11 mm and centered at approximately 5.6 mm. When converted to coefficients of shrinkage, the aforementioned distribution is in a range of about 0 to 5.6%, centered at approximately 2.8%. The largest coefficient of shrinkage observed is similar to the coefficient of air-dry shrinkage (the coefficient of shrinkage when the green moisture content is up to 15%) found in the tangential direction of Cerasus jamasakura wood, the material used for woodblocks in Japan. Similar coefficients of shrinkage were often found among every set of four adjacent double-folded pages, and it is thus estimated that the phenomenon in which the printing area shrinks when producing facsimile editions results from air-dry shrinkage of the woodblocks.
A similar phenomenon was observed in the horizontal direction of these editions, though the values measured in the horizontal direction of facsimile editions shifted by about 1 to 2% toward an expanding direction. Considering that woodblock-printed books shrink by about 1 to 2% only in the horizontal direction as compared to their woodblocks, it is thought that the expansion and shrinkage of the paper (washi) contributes to this shift in the values. Paper
expands and shrinks more in the radial direction of its fibers, and the radial direction of fibers in ōhon generally corresponds to the horizontal direction. The following series of events is thought to have produced the observed results: when producing a facsimile, the paper serving
as the basis for the woodblock carving is stretched out and affixed onto the woodblock with paste, and hence the facsimile edition becomes longer in the horizontal direction ; later, when printing a book with the woodblocks, the paper for printing is kept moist beforehand and thus
grows longer, though it shrinks in the horizontal direction through drying after printing.
It is expected that these phenomena of expansion and shrinkage in the printing area occur with all woodblock-printed books in a similar fashion. When this hypothesis was examined regarding the original editions of three texts mentioned above with the assumption that the paper used as the basis for the woodblock carving featured identical ruling lines, all three showed similar coefficients of shrinkage.
The shrinkage observed in woodblocks was irregular, apart from the trend of similar degrees of shrinkage being found among every set of four adjacent double-folded pages. Hence, the shrinkage had a unique continuity for each group of woodblocks, that is to say for each edition.
This indicates the possibility for different editions (specifically, books of the same text printed with different woodblocks) to be identified by comparing the distance measured between printed page borders. This possibility was confirmed by comparing various editions of the three texts mentioned above, as well as different editions of Rinzairoku (Chinshū Rinzai Eshō Zenshi Goroku).
Measurement of the distance between printed page borders can be performed mechanically by detecting two lines (one at the top and one at the bottom of each border) in digital images. The identification of different editions conventionally requires refined techniques on the part of experts, though this new method is expected to enable a simplified identification process to be performed mechanically.
Finally, this study examined an edition of Wen Xuan printed in 1555 A.D. in the domain of Tang and a facsimile edition produced from it, as an example of books printed in China and then imported into Japan. With these two editions, while no trend was observed in which degrees of shrinkage were similar among every set of four adjacent double-folded pages, the distributions were similar to the three texts mentioned above, albeit with slightly different
degrees of shrinkage. However, because the paper used for these editions has a different orientation to ōhon in Japan with respect to the horizontal and vertical axes, the phenomenon seen in the horizontal direction of ōhon in Japan was observed in the vertical direction of the examined Wen Xuan editions, and the values measured in the facsimile edition shifted toward an expanding direction. With books printed in China, the paper can be used in two different orientations, and thus care is needed in this regard. The reason that no trend was observed in every set of four adjacent double-folded pages is thought to be related to the configuration of the woodblocks, and the difference in the coefficients of shrinkage is thought to be related to the difference in the material used for woodblocks, since jujube, pear, and boxwood were used in China.