The Japanese papermaking company Onao and designer Naoto Fukasawa have teamed up to create the Siwa line of products. All Siwa products are made of Naoron, a special type of paper which consists of wood pulp and synthetic fibers (see picture right). Onao based its production upon an ancient Japanese manufacturing process: washi-suki. There are two types of Naoron: Soft Naoron, a mixture of wood pulp and polyolefin fibers making for a soft and flexible texture and RPF Naoron (Recycled PET Fiber), a pulp to which recycled polyester fibers from bottles and rags have been added.

Both types do not emit noxious fumes when burned. The material is water resistant and hard to tear while still retaining its distinctive paper texture. In the Siwa products Fukasawa aims to emphasize the characteristic wrinkly texture of paper. The name Siwa derives from the word ‘Shiwa’, meaning ‘wrinkle’ in Japanese. At the same time it is an acronym for Washi.