Pebbled cloth or leather describes the covering of a hardcover
book with a decorative texture of repeated small raised bumps, somewhat
resembling tiny pebbles one supposes.
First introduced around 1860, pebbled decoration on the cloth or leather
covering the boards of a book
became a common method of adding a decorative texture and is still used
in some cases by contemporary publishers, although more commonly now to
give an antique appearance to a new book.