Public Domain Review shares some gorgeous examples of book design from over a century ago, when books were more than (hopefully great) writing in an appealing package—they were physical works of art in and of themselves.
Many of these might also have been covered with dustjackets, but not only were they less likely to survive to our modern times, they might have been much blander versions of the actual book covers.
Throughout the nineteenth century, nearly all dust jackets were discarded at or soon after purchase. Many were probably discarded in bookstores as the books were put out for display, or when they were sold; there is evidence that this was common practice in England until World War I. The period from the 1820s to 1900 was a golden age for publishers’ decorative bookbinding, and most dust jackets were much plainer than the books they covered, often simply repeating the main elements of the binding decoration in black on cream or brown paper.
I can easily imagine discarding dustjackets to show off these covers on my bookshelves.
What strikes me is the flair added to what are mostly decidedly minimalist designs.
Some of these seem to anticipate the Art Deco era.
Some of these cover designs are dreamlike.
The next three I find beautifully haunting.
More info, book scans, and download links for these books and many others are linked from the Public Domain Review.