Fanzine and self-publication history can be traced from the invention of the printing press. Large scale printed sheets in various sizes with text reporting news were, satire and literature, and religious thoughts also self-published in that era, to spread message to a wide audience.
Little-magazines or self-published political publication emerged just before and after World War 1 period (1950’s) that’s also quite similar to fanzines. Then came Dada publications that can be said as proto-zine which also self-published for pleasure or creators and readers, short-lived and ignoring all standards and rules. After that there were surrealist journals that were also self-published.
The mimeograph revolution came into picture in 1930’s and was at the high stake during World War 2 with hundreds of zine-like resistance publication produced by leftists. Fanzine was invented by science-fiction enthusiasts in 1950’s. It typically focuses on concepts, rumors, fads and similar phenomena rather than commercial promotion.
Nowadays fanzine producers use word processing, design program and internet on computers, it’s all easier.
reference: Vale, V. 1996. Zines! Vol. 1. San Francisco: V Search.