Persephone Books is a small London book publisher on a wonderful shopping street called Lamb's Conduit, which I discovered on a retail tour led by Clare Dowdy, author of One Off, about unique retailers worldwide. (Arrange Dowdy's tour through the InterContinental Park Lane London.)
Persephone, which celebrates its 10th anniversary this year, publishes just 83 books, and ones you won't easily find elsewhere -- neglected classics by 20th century writers who are mostly women. Their books are bound in an elegant dove gray, and the endpapers are unique to each book, and are prints of antique fabric designs. (You can get a matching bookmark.) It's fun to visit the store and hard to buy just one -- I walked away with An Interrupted Life: The Diary of Etty Hillesum, and The Journal of Katherine Mansfield -- although you can also order online.