The first three books are in a slip cover and are paperback. Books 4, 5, and 6 are paperback. Book 7 is a hardcover. Books have all been read and are all at least in fair condition. All are clean, with no marks inside. Some discoloration inside front and back covers as shown in last photo. This is not from water damage and appears to be just from the paper degrading over time. From a pet-free, smoke-free home.