Mr. Sonobe carried out his own personal technological innovation and established his marbled pattern technique based on Mardley dyeing (norinagashi-zome, a paste-dyeing technique), which he learned at the workshop he was apprenticed to when he was young. With norinagashi-zome, a large quantity of paste is used in the process to produce a mardley pattern, and the process of removing the paste is extremely burdensome. Sonobe Senko spent 10 years researching ways to alleviate this. With the development of a dye that does not dissolve easily in water, the company established a marbling technique that could be carried out more efficiently and that produced beautiful results.
This drive to take on challenges has not stopped; they have dyed leather using dyeing techniques used with the woven silk fabric used for making kimono, and continue with their technological innovations so as to clothe as many people as possible in beautifully dyed products.
Yuzen-dyeing is the general term used to describe the practice of drawing pictures using dyes made up of water and fine particles that has been handed down for more than one thousand years. The dye permeates to the core of fabrics such as cotton and silk and colors them, resulting in a deep color whose appearance changes according to the way the light hits the dyed cloth. Sumi-nagashi, the art of creating marbled patterns using dye, is said to have originated during the Heian period from a pastime of the nobility, who dripped Indian ink into water and enjoyed the way it flowed. The sentiment implied here can be seen in the phrase “mizu ni sumi wo nagasu” (pouring black ink into water ), which incorporates the phrase “mizu ni nagasu” (to let bygones be bygones) and a pun on the word for the color of the ink (“kuro” – black) with the word for hardship – “kurou”; it is said to be a fortuitous pattern. The most appealing aspect of this pattern is that owing to the flow of the water and the handwork of the artisans, no two patterns are the same – they are all one of a kind.
White calfskin is placed on top of the pattern that is created, which is transferred to the leather.