boards : Common term for the covers of a hardbound book.

Marbled boards : A hardcover book with a decorative, multi-colored paper on the outside covering.

8vo : Short for Octavo, A book whose page size is approximately 8-10 inches tall. The size is based on a sheet of paper 25 inches by 38 inches, the size of paper traditionally used by book printers, which has been folded and cut into 16 pages.. Unfortunately often misunderstood to mean 8 volumes.

Cloth : Generally refers to a hardcover with cloth covering the outside of the book covers.