Today, many teachers and students probably think nothing of copying a document. If it’s printed on a sheet of paper, off to the copy machine it goes. And in our digital era, with Chromebooks and other electronic devices in students’ hands, the cloud has taken over basic document processing in an extremely effective way — no paper necessary.

But before all that, there was a device that came to define printed documents in classrooms for a generation, one hand-crank at a time: the mimeograph machine. Let’s talk about why this device, and its close cousin, the spirit duplicator, mattered to K–12 classrooms.