Illustrated popular fiction published in Edo from the mid-17th to the late 19th century. Narrative and dialogue was written in kana 仮名 in the blank spaces of the full-page or half-page illustrations. Because illustrations were crucial, the books are also called *ezōshi 絵草子. The kusazōshi is thought to have originated around 1662. There are several explanations for the origin of the word. One is that the cheap, smelly ink with which they were printed led to the name kusazōshi, which is thought to have originally meant "smelly books." Another explanation is that the character kusa 草 has the same meaning as in the word kusazumō 草相撲 (local wrestling match) in that the books were informal and a contrast to proper and regular forms. The characters sōshi 双紙, also written 草子, meant book or booklet. Originally, books which were intended for learner readers were all called kusazōshi. In the early stages, illustrations were often designed by the writers themselves, but later woodblock *ukiyo-e 浮世絵 print designers began to work as book illustrators. Kusazōshi were produced on inexpensive Mino paper *minogami 美濃紙 in the form of slim booklets, each containing five double pages measuring about 19 cm x 13 cm. The term kusazōshi was used generally to describe books known by the color of their cover, type of binding, or content: *akahon 赤本, *kurohon 黒本, *aohon 青本, *kibyōshi 黄表紙, and *gōkan 合巻 can all be considered kusazōshi, although kibyōshi and gōkan, because of their wider range of contents, are also considered part of the genre of popular fiction known as gesaku 戯作. As plots became more complex, the increasingly longer stories were produced in multivolume sets. Kusazōshi were produced through the end of the 19th century, eventually losing their readership to the development of serialized novels in the newly introduced daily newspapers.