The USPO Publicity Photo (sometimes referred to as Photo Essay) depicts the preliminary artwork of the stamp's design. These photos are usually prepared before the stamps are printed. The design in the photo will vary from the actual stamp. They are intended for use in print publications to promote the stamp. And also for first day cover cachet designers who must do their work before the stamps are issued. The photos are usually 3 by 4 inches or 4 by 3 inches on glossy black & white photo stock. The photo is considered by many collectors to be an important part of the stamp's development history.