Even posting this image of the mimeograph machine reminds me of the particular smell it gave off. If you are old enough to remember the machine, I bet the you would still recognize the odor if you ran across it. Since we needed more than one copy of a worksheet for much elementary school assignments, we had to use the mimeograph machine.
Fortunately, I rarely had to make my own stencils to use. There were many ready made mimeograph sheets available. But sometimes I had to make my own. I typed them on the stencil material which produced the image in reverse on the back of the master. Then the master was carefully separated from the back and attached to the large roller of the machine. Paper was inserted on the right and then you cranked the roller to duplicate as many sheets as you needed.
What could go wrong? You might die from the fumes of the thing to start with. There were no OSHA regulations in those days, and I am sure that the ink used to reproduce the stencil was toxic. Then you would have the challenge of attaching the master very carefully so that it lay evenly and smoothly across the roller. A slight wobble produced disastrous results. And of course, like most teachers I would wait until the morning I needed the sheets to run them off. So we had to wait while each of us carefully attached a stencil and ran off their copies.
Do I miss the thing? Not at all. By the time I returned to teaching the Xerox had been invented. Of course, it brought a myriad of its own problems from paper jams to toner spill. But at least, unless when it was overheating, it didn’t send out toxic fumes!