Artisans make traditional “washi” paper from late November to early December in Yoshino, Nara Prefecture. (Nobuhiro Shirai)

YOSHINO, Nara Prefecture—As the winter chill sets in, the production of traditional washi paper is in full swing at a historic workshop here.

Winter is the best season for paper making, since the cold water helps to evenly distribute the fibers, resulting in strong and flexible paper.

The kind of paper made at Fukunishi Washi Honpo is called “uda” and is an essential material for the restoration of cultural artifacts.

“I want to create paper without a single flaw, always reminding myself to make the best washi for our customers,” said Masayuki Fukunishi, 63, the sixth-generation owner of the workshop.

Uda paper is made from “kozo,” a type of paper mulberry tree.

Preparing the harvested kozo for paper making involves several steps, including soaking the kozo bark in the clear waters of the nearby Yoshinogawa river before leaving it for up to two years.

The processed bark is then boiled and beaten with wooden hammers for an hour to break down the fibers.

The resulting pulp slurry is then formed into a thin layer of paper using a screen before being spread out on a board and hung to dry in the yard.

Each sheet of paper measures 145 centimeters in length and 32 centimeters in width. On busy days, the workshop produces up to 180 sheets.