A number of sources of inspiration and information, in addition to books on costume history, are invaluable to the fashion designer and the historian of fashion. They include predictions of style and market trends, visual sources of creative inspiration, and a variety of forms of historical evidence. Sources of information on style and market trends include forecasting services, trade magazines, newspapers, advertising material, and fashion magazines. Sources from which the designer can draw inspiration include paintings and visual imagery from the theatre, cinema, and popular culture. Historical evidence includes portrait paintings, fashion plates and magazines, photographs, literary sources, pattern books, and trade catalogues. Above all, magazines and serial-type publications are crucially important, for the sake of their currency, and later from a historical perspective; access to magazines is facilitated by indexing services.