One of the most important recent contributions to the literature on nineteenth-century British book-bindings is: Edmund M. B. King, Victorian decorated trade bindings, 1830-1880: a descriptive bibliography, London and Newcastle, DE, 2003. In addition to providing a bibliography of 752 handsomely bound 19th century editions from the British Library, with full-colour reproductions of 64 of them, it includes exceptionally detailed descriptions of the decorative covers themselves. Bindings by a total of 26 identified designers are featured. This website has relied heavily on that publication as a source for the description of the book-covers which it showcases. Caution is needed, however, when trying to match a cover with that of an item in this bibliography because Victorian cover designers often produced multiple variant bindings for the same title which differ from each other in minor details that are not always immediately obvious.
Some other useful background sources:
Carter, John. Binding variants. London: Constable and Company, 1932.
Krupp, Andrea. "Bookcloth in England and America, 1823-50", Bibliographical Society of Papers. 100, 1, March 2000, 25-87.
McLean, Ruari. Victorian publishers' book-bindings in paper. Berkeley: University of California Press, 1983.
-----------------Victorian publishers' book-bindings in cloth and leather. Berkeley: University of California Press, 1973.
Nixon, Howard M. and Mirjam M. Foot. The history of decorated bookbinding in England.ed. edited Mirjam M. Foot. Oxford [England]: Clarendon Press; Oxford; Toronto: Oxford University Press, 1992.
Packer, Maurice. Bookbinders of Victorian London. London: British Library, 1991.
Sadleir, M. The evolution of publishers' binding styles, 1770-1900. London: Constable; New York: R.R. Smith, 1930.
Tomlinson, William. Bookcloth 1823-1980: a study of early use and the rise of manufacture, Winterbottom's dominance of the trade in Britain and America, production methods and costs and the identification of qualities and designs. Stockport, Cheshire, England : D. Tomlinson, 1996.