Photo/Illutration The right panel of the "byobu" under restoration features soldiers fighting during the 1614 winter campaign of the Siege of Osaka. (Rei Kishitsu)

A special project to reproduce the lost original of a pair of "byobu" folding screens depicting the 1614 winter campaign of the Siege of Osaka (1614-1615), is set to wrap up by late May.

The project aims to digitally restore the original illustrations based on replicas produced in the Edo Period (1603-1867).

Those art works are the only known byobu depicting the winter campaign as the original screens are presumed lost.

Artisans have been painstakingly working the old-fashioned way, armed with paintbrushes as the final phase of the project, after other members utilized the latest digital technology to reproduce original colors.

Project members began by scanning the byobu to create a digital image of it. They authentically restored faded colors and reproduced colors for blank areas based on instructions written in calligraphy on the screens under the supervision of experts. The process took over a year.

A special printer was used to produce an image of the byobu for the artists to work on. Skilled workers are currently carefully placing gold leaves on it to give it a 3-D appearance and hand-painting the screens to lend their colors a naturally uneven look.

There are numerous byobu of the Siege of Osaka's summer campaign, where the forces of Tokugawa Ieyasu (1542-1616) burned down the original Osaka Castle and wiped out the Toyotomi clan in 1615. But only one pair of byobu illustrating the winter campaign have been confirmed to exist today.

Toyotomi clan troops decimated Ieyasu’s forces at the Sanada Maru fortress during the winter campaign thanks to the efforts of Sanada Nobushige (1567?-1615), a warlord commonly known as Sanada Yukimura.

Now, the fortress is vibrantly depicted on the restoration of “Osaka Fuyu no Jin Zu Byobu” (byobu of the winter campaign of the Siege of Osaka).

The pair of centuries-old byobu owned by the Tokyo National Museum in Taito Ward are about 1.8 meters high and 7.2 meters wide in total. They show the original Osaka Castle and a whopping 2,300 people, including Toyotomi Hideyori (1593-1615), the son of Toyotomi Hideyoshi (1537-1598); and Hideyori's mother, Yodo, who was a high-ranking concubine of Hideyoshi; and Yukimura.

No one knows who created the byobu copy, which likely was made as a model for painters in the Edo Period, based on the original, whose whereabouts are unknown.

Portions of the byobu only bear instructions for colors and were never painted.

“There were many kanji characters in the instructions that were difficult to read,” said Yu Kinoshita, 36, creative director of digital cultural properties at Toppan Printing Co., who heads the joint project of Toppan Printing, the Tokugawa Art Museum in Nagoya, the Tokyo University of the Arts and Yoshihiro Senda, a castle archaeology professor at Nara University.

“After colors were reproduced, the details became understandable. I think this will be helpful for historical research,” Kinoshita said.

The byobu are expected to be completed soon and be put on display from July 27 during an exhibition at the Tokugawa Art Museum.