In 1928, Walter E. Diemer, an accountant for the Fleer Chewing Gum Company in Philadelphia, was experimenting with new gum recipes. One recipe was found to be less sticky than regular chewing gum, and stretched more easily. This gum became highly successful and was eventually named by the president of Fleer as Dubble Bubble because of its stretchy texture. The original bubble gum was pink because that was the only dye Diemer had on hand at the time and it was his favorite color. In modern chewing gum, if natural rubber such as chicle is used, it must pass several purity and cleanliness tests. However, most modern types of chewing gum use synthetic gum based materials. These materials allow for longer-lasting flavor, a better texture, and a reduction in tackiness.