In case you haven't seen these...I first heard about Coralie Bickford-Smith's designs on Design Sponge. They're so beautiful I couldn't resist not passing this along. She's a senior designer at Penguin Books and recently designed their hard-bound classics as a series. Each cover has a different pattern, using a symbol inspired from the book itself, 2 colors and a metallic finish. Each one is so unique yet clearly part of a collection. See the interview on Design Sponge here. See Coralie Bickford-Smith's website here.