mimeographs

Mimeographs, also known as stencil duplicators, are mechanical devices used to reproduce text and images on multiple sheets of paper. They were widely used from the early 20th century through the 1960s and 1970s for schools, churches, clubs, and small offices before photocopying became common. A mimeograph creates copies from a master stencil prepared by typing or drawing on a wax-coated sheet. The raised or cut areas of the stencil block ink from a reservoir and allow it to pass through onto blank sheets as they are fed through the press.

Most mimeographs use a roller and drum mechanism. The ink, typically a purple or blue mimeograph ink, is applied to the stencil and pressed through the stencil apertures onto paper. Each copy is produced by running a fresh sheet through the machine, yielding consistent results until the master wears out or becomes overused. The process is relatively inexpensive and can produce dozens to hundreds of copies, depending on the machine and ink supply.

Variants include the spirit duplicator, often called a ditto machine, which uses a separate wax master and a solvent-based transfer process. Spirit duplicators produce a distinct, usually lighter-colored copy. Mimeographs require manual setup and ongoing maintenance; common issues include misalignment, smearing, and ink bleed.

Decline came with the rapid spread of photocopying and digital printing in the late 20th century, but mimeographs remain associated with early grassroots publishing, school newsletters, and archival documents. Some enthusiasts collect old mimeograph machines or recreate the look for zines and educational materials.