You may also know these devices as the Banda machine. You will certainly know the Banda machine if you were a schoolteacher during the middle decades of the twentieth century.
These were the days before photocopiers or computers and their associated printers. If you wanted to give a school handout to a group of 30 or 35 pupils, your only available method — apart from copying out the wretched thing in your best handwriting — was to make a Banda.
Making Banda copies was an involved process. First, you created a master copy on a two-layered sheet. You typed, wrote or drew on the top sheet. Below the top sheet was a dark-coloured sheet, coated with a layer of wax containing colouring agents. When you typed, wrote or drew on the top sheet, the pressure of that writing would transfer the coloured wax from the lower sheet onto the shiny underside of the top sheet, producing a mirror image of what you needed to copy.
You fixed that mirror image “spirit carbon” to the drum/roller of the Banda machine. You then grabbed a rotating handle to turn the drum. The blank paper in the in-tray went over an absorbent pad soaked with solvent; some of the coloured wax dissolved and was left on the paper as it passed over the drum. Into the out-tray arrived your copies; mirror images of the mirror image, so perfectly legible again.
Those resulting slightly fuzzy copies, usually in purple ink, bore the unmistakable fragrance of the solvent: methyl alcohol. The aroma wafted about your person as you entered the classroom. Depending on how recently you had made your copies, your students could spend the entire lesson poring over their Banda sheets in a vaporous alcoholic haze that made them slightly fuzzy themselves. Not the state of mind most conducive to absorbing the intricacies of past participles or notable dates in history.
Photocopiers and printers announced the march of Progress. The sweet fragrance of the spirit duplicator belongs only in the school corridors of old. The only reason I still have some legible Bandas is that they’ve been stored in a box in an attic. Their fuzzy images gradually fade on exposure to ultraviolet light. I doubt, therefore, if any of my former students still sentimentally retain my handwritten instructions on the dialects of Middle English.
Progress has its price. The spirit duplicator was clunky but quick and cheap in comparison to many printers. Plus, it had an unforgettable aroma.
Also, sigh, your Banda machine never suddenly announced that it couldn’t “access” the printer.