When I was in primary school, back in the day before ubiquitous printers and copiers – aka the early ’90s – our worksheets were printed in fuzzy purple letters. They were produced by rubbing paper on trays of jelly, with the shapes and letters of the worksheet embedded in the jelly. We didn’t know how those shapes and letters got there – one of the many mysterious things that happened in the staff-room, the office, the behind-the-scenes parts of the school hidden from the students.
Sometimes – probably because she just had too much else to do – the teacher would get one of the kids to print the class’ worksheets. I don’t know how often this happened – all I have is a memory – just a flash, a picture – of watching another kid carefully placing and rubbing sheets on the tray, and wishing that just once I would be chosen for the job.
For years I’ve wondered what that stuff was, and I’ve finally found it. A random wiki-trail led me to duplicating machines, and thence to hectography. A twenty year mystery solved! Apparently it was used in WWII by prisoners of war to secretly make and copy escape maps (by hiding and then melting down their jelly desserts!). It was also used to print postage stamps in rural China in 1948.
Now I want to try it myself. It looks like all I need is gelatin, aniline dye, a cooking tray and some paper… I’m not sure about the dye, but the rest is easy to acquire. Will have to experiment with household pigments. Time to write me a ‘zine – ideally full of subversive ideas or bad fanfic, or both.