A more recent ad (not 20s) for Fleer's Dubble Bubble Gum
In 1928, Walter Diemer (accountant at Fleer gum) stumbled upon the formula for making a gum whose bubbles didn't stick or injure the chewing party. This was a new phenomenon for the gum chewing community, and so the ads contained odd warnings about bubble gum being "poisonous." This was also one of the first times that food coloring was used - the pink color Diemer chose became the industry standard.
