In recent years, the collecting card industry has exploded exponentially. During the early years of the twentieth century, cigarette companies added a card to their packs to stiffen them. They soon learned that people saved, and collected the cards, if they were marked with a celebrity image. Later, the same was true of bubble gum packs, except one thin sheet of gum usually accompanied a selection of several cards. Baseball cards were the most widely collected at midcentury. However, since about 1970 celebrities of every stripe, from singers to cartoon characters, can be found on collectible cards. Disney characters are no exception.