Looking at the Discovery of the Printing Press with an X-Ray Microscope

Looking at the Discovery of the Printing Press with an X-Ray Microscope
Looking at the Discovery of the Printing Press with an This information can help understand the earliest printing techniques. Ref: SLAC

The printing press is called the most important invention of the last thousand years. This honor has often been given to Johannes Gutenberg, a 15th-century German craftsman. But 78 years before Gutenberg printed the first copy of the Bible, a collection of Buddhist teachings from Korea called Jikji Simchi Yojeol was printed using a printing press. How can the printing processes of Jikji and the Gutenberg Bible be compared?

Scientists at the SLAC National Accelerator Laboratory in California are using an x-ray probe to investigate this issue as part of a group study. From what scientists discover about the chemical structure of ancient Eastern and Western writings, they will gain insight into how cultural exchanges influenced the technological development of printing.

Jikji and the Gutenberg Bible are just two examples of earlier editions. The first printed scrolls were made by East Asian scribes in the eighth century. They would carve text images into blocks of wood, ink them, and then print the inked text onto paper. Over time, this method gave way to movable metal type printing as it is known today. A craftsman created these hardened metal writing groups by pouring molten metal into molds. The text created by these character “stamps” would then be placed on a board and dipped in ink and stamped onto a page.

Although the procedure seems simple to us now, artists at the time faced numerous challenges, such as choosing the best metal composition and perfecting the typesetting method. The UNESCO International Center for Documentary Heritage (ICDH) in Korea has conducted historical research showing that Korean scribes had mastered these problems enough to be able to print books using movable metal writing as early as 1234. A copy of Jikji from 1377 is the first documented example of this printing tradition.

However, Gutenberg is still revered as the creator of movable metal type printing. But the truth is slowly coming to light. The existence of a pre-Gutenberg printing press is evidenced by the recent discovery of movable metal type in Korea.

The French National Library also recognized Korea's importance as the origin of printing this summer with an exhibition that included works from the Gutenberg press as well as the earliest printed Jikji.

While the story of printing is being rewritten, there are still many unanswered questions about early Eastern and Western printing made with movable metal type. Uwe Bergmann, a physicist at the University of Wisconsin-Madison, has developed and applied x-ray spectroscopy technologies at SLAC's Stanford Synchrotron Radiation Lightsource (SSRL) for many years.

“The million-dollar question is: Was Gutenberg aware of Korean technology or not?” he asks.

Although it is unlikely that researchers will be able to detect Gutenberg's influences, analyzing the chemical structure of materials in samples from both print cultures will help researchers piece together their precise technique and any connections. Bergmann and his team collect this chemical data by imaging ancient manuscripts with high-resolution x-ray fluorescence (XRF).

At SSRL, the pages are placed in an x-ray beam line specially created to examine large, fragile samples for archaeological, medical and geological studies. This is how researchers collect their data. A single page is scanned by the beam, focusing on each pixel to obtain an XRF spectrum that can identify the chemical components of the paper and ink. “When we first started XRF imaging at SSRL years ago, we could only monitor ten [chemical] channels per pixel. According to Bergmann, we can now collect the entire XRF spectrum, as there are almost 2000 channels available at each pixel. For printed manuscripts, the result is a page-by-page, up to 5-megapixel x-ray image that can be acquired within a few hours.

In 2022, Bergmann and colleagues examined pages from dozens of samples of Korean and Gutenberg manuscripts written before 1500. The presence of extremely high levels of metals such as copper and lead in both pressure groups surprised the researchers. “We are trying to understand whether these observed metal signals are related to the types of metals used for printing,” says Angelica Noh, a member of the ICDH team.

To investigate this potential connection, researchers are reproducing early printing methods using a variety of inks and layers. This “historical recreation” offers the opportunity to compare the fine-scale chemical details on the reproduced pages with those in historical copies, as Bergman discussed at the Canadian Chemical Society meeting this summer. According to Bergmann, “our initial work on self-made prints examines whether and how much metals from species can leach into the print.” They are also exploring additional scenarios, such as adding metals to the ink to act as a drying agent.

Despite the early stages of the project, it is hoped that the research will fill gaps in our knowledge of early printing techniques. In particular, little is known about the types of materials used in printing in the Middle Ages in Europe. “If we can confirm that metals leach into the ink, we can use this information to learn more about the composition of types used in Gutenberg and other early Western prints,” adds Bergmann. Information about Korean metal types, many of which still survive, can be compared with this information about the alloy. Evidence of technological transfer between East and West can be found in potential parallels.

Whatever its exact origins, movable metal letter printing has left a lasting impact on human society. Bergmann and his colleagues are preparing a multi-country show for 2027 as part of Jikji's UNESCO heritage anniversary. Bergmann explains: “We want to announce the birth of this technology to the world.

Source: physics.aps.org/articles/v16/154

📩 09/09/2023 23:05