Steidl gives an interview to The Talks. He discusses taking time off, when a book really becomes a book, and how he gained so much knowledge about printing.
It was just learning by doing. When I started, I was working as a screen printer and I learned about screen printing technology from Andy Warhol and his manager Gerard Malanga. The same with etchings and stone lithographs and later with offset printing. You can always find a guy somewhere who knows about these technologies. I was young, I was 20, 25 years old, and of course they were proud to give their knowledge to me. The rest is doing experiments and testing and not giving up. If something is not satisfying start again, turn everything upside down and find a new formula for printing. Everything is learning by doing.