Tosa Washi is characterized by its wide variety, and its thinness and durability compared to other types of washi. The area around Ino-cho and Tosa City, where it is produced, is home to rivers renowned for their purity, such as the Niyodo River and the Shimanto River.

In addition, the "Kozo (paper mulberry)" produced in the mountainous areas of Kochi Prefecture is characterized by its long fibers that easily intertwine with each other. Tosa's Kozo and beautiful river water produce thin and strong Tosa Washi. It is truly a craft produced by nature.

The remaining washi production areas throughout Japan produce fewer and fewer varieties. However, Tosa Washi continues to produce about 300 various types of washi even today.

"Rakusui" paper is a type of Washi Paper in which water is dropped onto the surface when thin paper is being made, creating patterns on the surface. The paper is characterized by its lace-like appearance with holes. The speed of paper-making, which can reach several meters per second, and the intuition of the craftsman who adjusts the material mixture by grams are important to create the beautiful swirls of the Rakusui pattern. The method of carefully crafting with wisdom and ingenuity is the same today as it was in the past, even with the help of machines.

Sukiawase is a technique to make a duplex structure sheet by adding another sheet of Washi Paper to the back of Rakusui paper.

Its history dates back about 1,000 years. Since the name of Tosa Washi appears in the "Engishiki", a set of regulations compiled in the Heian period (794-1185), as an offering, it is thought that washi was being made in the area from that time.

At that time, washi was considered valuable and was used for shell-matching game called "Kaiawase" and other aristocratic games. As time went by, the use of washi changed and it was used for samurai's kimonos, dolls, paper money issued by a feudal clan, and so on.
Even in the Edo period (1603-1867), Tosa Washi was an important specialty product, being considered an offering to the shogunate, and was protected by the Tosa Clan.

With the development of new techniques and tools, Tosa became the largest producer in Japan from around 1887 to the beginning of the Showa period (1926-1989), and exported typewriter paper and copying paper.