The stencil duplicator or mimeograph machine (often abbreviated to mimeo) is a low-cost printing press that works by forcing ink through a stencil onto paper.

Along with spirit duplicators and hectographs, mimeographs were for many decades used to print short-run office work, classroom materials, and church bulletins. They also were critical to the development of early fanzines because their low cost and availability enabled publication of amateur writings. These technologies began to be supplanted by photocopying and cheap offset printing in the late 1960s.

Although in mid-range quantities mimeographs remain more economical and energy efficient, easier-to-use photocopying and offset have replaced mimeography almost entirely in developed countries, although it continues to be a working technology in developing countries because it’s a simpler, cheaper, and more robust technology, and because many mimeographs can be hand-cranked and thus require no electricity

Illustration of a typical mimeograph machine.