Marshall Vandruff had two online courses on what we can learn from the Heinrich Kley illustrations, and you can learn a lot from these courses and Heinrich Kley!
Marshall may be the best art teacher in the world right now. His course is worth checking out. He put his Bridgman course on YouTube for free! You can find the playlist here.
Both Heinrich Kley courses covered the same ground, but to my surprise, I found myself picking up things that had not stuck the first time. I went back to my notes, and Marshall had mentioned it the first time. The videos are just so packed with information.
They also cover much of the same ideas presented in the Bridgman course: a successful drawing (of a pose) considers the underlying three-dimensional form and how you can imaginatively invent some of it also, the shapes formed on the page, the gesture (and the story it tells, considering what happened before, what will happen after).
I also found a book from 1912 and made high-resolution scans of the Heinrich Kley illustrations.
You can find Marshall’s Heinrich Kley course here. It does cost money, but it’s relatively cheap.
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