With regard to Dharanis (Buddhist charms which are one of the world's first printed papers), I focused on the aspects of printing and paper, looked back on the past findings, and described the results of the research carried out in the area since the beginning of the Heisei era. However, I have not yet arrived at a conclusion on the woodblock theory, according to which, Dharani was printed on a woodblock, and the copper letterpress theory, according to which, they were printed on a copper plate. Dharanis were housed in a million wooden towers. It was revealed that the cypress tower itself adjusted the humidity and protected Dharanis for 1,300 years. The reason why Dharanis were housed in the hollowed-out body of the million towers and were covered with ring roof parts, was based on a scientific effect for preservation.

In the middle ages in Japan, books about Buddhism were printed in temples with the use of woodblocks; however, literary works were not. Limited people could read them in the form of a manuscript. By the end of the 16th century, the technology of letterpress printing came to be introduced from Korea. Authorities started printing and printed not only academic books, but also classic literary works such as The Tale of Genji. Within a short period, printing and publishing businesses rose in the public sector and reading narratives became an entertainment throughout the Edo period. People would make new works based on classics and original works, especially after the center of business moved to Edo (Tokyo). By the mid-17th century, the printing technology they used went back to woodblock from letterpress, making the expressions and the publishing system unique to Japan. In the last days of the Tokugawa shogunate, there was a flooding of Western culture, Japanese people again started using letterpress printing as they acquired a new casting method, and the modernization of literature progressed. Printing Museums, Tokyo named the revival of classics as “The Renaissance of Japanese classics,” after the renaissance, and held an exhibition about those movements. By looking back at the exhibition, I described the relationship between printing and the development of Japanese literature.

Invented in 1854 as a photographic printing technique, the collotype process spread throughout the world, especially in Europe and the United States, owing to its exquisite rendering of tonal gradations and excellent archival quality. When it was introduced in Japan by the end of the 19th century, it was initially used mainly for illustrations in art books and played an important role in popularizing Japanese art within Japan and abroad. From the Taisho and Showa eras, the number of collotype printing studios increased in Japan, but gradually decreased after 1970, when other printing technologies emerged. Benrido opened a collotype studio in 1905 and started producing postcards and photographic illustrations, and reproducing cultural properties using the collotype process. Among them was the full-scale collotype reproduction of the wall paintings of the Main Hall of Horyuji Temple. Produced by Benrido in 1937, these reproductions are representative of the best qualities and characteristics of the collotype process. In addition, collotype technology developed in accordance with time. The works of color expressed via collotype through multi-color printing and the adaptation of new digital technology in the process have played an important role in supporting culture and art till today. While there have been many developments, collotype printing has been facing a decline in use, even from a global perspective. Therefore, there have been efforts put forth by individuals and organizations specializing in collotype work to preserve and promote the process via activities such as the “Society for the Preservation of Collotype Technology and Printing Culture” and the “International Collotype Conference.” Furthermore, Benrido started developing environmentally-friendly research and collotype practices so that the collotype technique is continued to be used. It is important to preserve the printing culture of collotype for the future and to further share information on the collotype's history and its contemporary process.

On June 30, 1998, the Stanhope Printing Press, in the possession of the Printing Bureau, was designated as an important cultural property of Japan. There are various theories as to when this printing press came to Japan, including 1849, 1850, 1858, and 1848-1859 to be the speculated periods, but none of them are beyond the realm of speculation. The first time anything was published using this printing press was a drawing of the nameplatea. This was in the 1944 edition of Ishii Kendo's “The Origins of Meiji Things, Revised and Enlarged,” which provided a rubbed copy of the nameplate of the printing press. Since it was a rubbed copy, the letters are shown in opposite, one could barely read the name “Amsterdam.” When it was turned upside down, one could read the name of the factory as G. van Heerde. In 1855, a printing shop was built in Nagasaki, although there was no printing press then. When printing is done on a printing press, an iron frame called “chase” is always attached. However, it seems that the printing presses were not used, as the type set showed a curvature in the string. Hence, it can be considered that the printing was done by hand at the time. It was also found from the type sample book of Tetterode that [p] was used with [d] upside down and [S] type was used upside down. “Diary of the Director of the Dutch Trading Post” of Nagasaki has been researched and investigated to understand how the printing press was presented to the Tokugawa Shogunate in the 4th year of Ansei (1857), which was taken over by Bansho Sirabesho and established around the same time, and passed on to the Ministry of Education and the Printing Bureau via the Tokugawa's Numazu Military Academy in Shizuoka Domain during the Meiji Restoration.

“Ichigaya Letterpress Factory” pre-opened in November 2020 and was open to the public in February 2021. The concept of this museum is “real factory.” The interior and exterior of the building were restored to the appearance of a letterpress printing factory from the Taisho period to the early Showa period. Many machines are displayed in motion, and visitors can operate them. In this report, we describe the outline of the museum, the method adopted to restore the building nicknamed “Clock Tower,” and the method adopted to restore the old letterpress printing machine to a working state.

A single-shot imaging system through the use of parallel phase-shifting digital holography has been developed for the detection of transparent defects in transparent coatings. Using this system, the solidification process of a transparent liquid thermoplastic resin coated on a glass substrate by the spin-coating technique was investigated under an in-plane temperature gradient. Transparent defects in the transparent coating were detected as the in-plane variation of the optical phase distribution originating from the differences in the optical path length between the non-defect and defect areas. In addition, the completion of the solidification of the resin coating could be determined by analyzing the time dependence of the phase distribution carried out during the solidification process.