Even though the books I’ve chosen for my current project are not children’s, I’ve found the book “Children’s book covers : great book jacket and cover design” by Alan Powers quite useful for my research.
The concept of illustrated book covers in adults’ books is a somewhat recent thing. Before, only children’s books would have illustrated covers. For this reason, when researching illustrated book covers from the past, I had to look into the children’s category as well.
“At first glance this looks like a coffee table book, but the author, a writer, curator, and lecturer on architecture and design, has created a knowledgeable historical survey of British and American book boards and jackets beginning with 17th century chapbooks. (…) The arrangement of the books is chronological, within that, the groupings are interesting.”
In this book I found some really nice examples, specially from the 30’s and 40’s onwards, which have inspired my own designs.