mimeograph

A mimeograph, or mimeo, is a duplicating device used to produce multiple copies of a document from a single master stencil. The basic principle is printing ink through holes cut or etched into a stencil onto sheets of paper, offering a cheaper alternative to a full printing press for modest print runs.

The master stencil is created on a special stencil sheet or by carving into a wax-coated sheet. The stencil is mounted on a drum or flat bed in the mimeograph machine. As paper passes through, an ink roller applies ink to the stencil, and the ink is transferred to each sheet to produce copies. The process can be adapted for single-color or multi-color output, depending on the machine and stencil arrangements.

Mimeographs gained widespread use from the late 19th century into the mid-20th century, particularly in schools, religious groups, small newspapers, and offices that required medium quantities of copies at low cost. They were valued for their speed, portability, and relative simplicity, especially before the advent of inexpensive photocopiers. Typical mimeograph work produced sheets with a distinctive blue or purple ink and a slightly uneven tone.

Over time, mimeographs were gradually replaced by plain paper copy machines and photocopiers, which offered higher quality and greater convenience. Today, the mimeograph is viewed as a historical tool central to mid-20th-century office and classroom practices, and the term “mimeo” remains a colloquial reminder of the era of stencil-based duplication.