What were those terrible tissue paper copiers called in the 1970's?

[Acsenray]

Spirit duplicators (ditto machines) and mimeographs are two different things. It’s ditto machines that had the purple ink and strong smell.

[Acsenray]

I remember that one of my teachers used to take his dittos and use some kind of process to “burn” the writing onto a transparency sheet, which he would then use on the overhead projector. I never know what that burning process was.

[eburacum45]

Heh heh; reminds me of when I went out with a teacher in the 70’s; after a party she threw up over her banda copies- purple vomit everywhere…

[Tom_Tildrum]

ISTM that a lot of science fiction from that era featured that flimsy thermal paper --lots of information circulating on fax-type machines and printed out on little slips that were often actually called “flimsies” or something similar.

[Leo_Bloom]

And I thoughti made up the word “flimsies” just for my post above.

::sound of deflating ego::

[Tom_Tildrum]

@Leo_Bloom

And I thoughti made up the word “flimsies” just for my post above.

::sound of deflating ego::

Heh. This would have been funny coming from Hari Seldon.

[gotpasswords]

@Acsenray

I remember that one of my teachers used to take his dittos and use some kind of process to “burn” the writing onto a transparency sheet, which he would then use on the overhead projector. I never know what that burning process was.

That would be a 3M Transparency Maker. Oddly enough, those dinosaurs are still seeing regular use at tattoo shops.

I used to work at the school’s AV department, and I probably made a couple thousand “overheads” on one of those machines. AFAIK, the process steals a bit of toner from the original - just a guess there, but I do recall there was a lot of heat involved and no ink or toner for the machine itself. I also recall that the process involved so much heat that the machine coud self-destruct if it jammed - there was a sign on the thing that if it jammed, the user was to immediately pull the plug and open the lid.

[CaptMurdock]

@Kiwi_Fruit

I remember Gestetner machines. I looked them up and found they were similar to the mimeograph in process. Also called cyclostyle, which was an alternative term used at school.

They produced a black printed sheet without the characteristic smell or purple print of the spirit duplicator, which I can’t for the life of me remember what we called. It may have been banda machine, as in the UK.

A sci-fi convention that I worked at back in the early nineties used a Gestetner. I remember thinking they were the evolutionary missing link between the mimeograph and the photocopier.