What is the fine-grained topic of the following text: Toyoaki Kuwayama, the successor of this family business took the company in an unexpected direction by applying a laborious dying process known as kyo-yuzen, a technique traditionally reserved for high end kimonos, to denim fabric. Only return the topic.
Applying Kyo-Yuzen Dying Process to Denim Fabric by Toyoaki Kuwayama