When my dad made the switch from projector slides (yeah, with a light bulb and actual physical slides made out of tiny photo negatives), I remember spending hours scanning in all of his old presentation materials so he could integrate the Old Analog and New Digital materials. The 1990s were a wild time.
That’s nothing compared to what people in the legit olden days had to do (I’m talking World War II). According to L. H. Mouat in the Quarterly Journal of Speech (1945):
The illustrated speech is done with posters, 20 by 40 inches, hung on an easel, so that they can be easily flipped back as the speech progresses. On each poster (their number may vary from 20 to 80 or more) illustration and copy are integrated by adequate layout. The copy is usually a brief statement roughly equivalent to a subdivision of the speech outline. The wording is not so formalized, however, and often transitional phrases are included.
My dad and I spend many hours making talks, but never as many days as someone who actually had to make 80 or more posters to hang on an easel had to do for their illustrated speech in the 1940s.
Happy Birthday, Dad, and thanks for teaching me about new technology!