“Black book” is a nickname used for journals kept by artists, writers, and thinkers. The name is derived from likely the classic moleskin book which was black leather bound, with blank pages and an elastic to hold the contents of the book together.
This could have been particularly necessary given the wide variety of ways black books are used for painting, note taking, collage, collecting of ephemera and much more. If you’ve never used and/or seen a black book you might peruse this search on Flickr for ‘moleskin.’ You’ll most likely see artists’ drawing and painting, as well as graffiti sketches. But look long far done the results and you’ll see many other uses of black books as well.
I myself used black books for a long time through both my undergraduate and graduate years and even after. I still have my first black book and it’s a confusion of art, science, religion, and safety – particular interests at the time while studying art and chemistry in college. In critiques as a graduate student peers would present works completed toward their degree in art, often in tow was their black book and often we would see the inspiration for the ‘completed’ works presented.
What invariably would happen in the these critiques was an interest in the works in the journal that often complimented the discussion and led to interest in pursuing new directions for the student. The effort in the books were typically intense and continuous in way that the final pieces presented were not. They were wonderful reflections of the artist and their thinking.