Canning novelty. Early methods of manufacture employed poisonous lead solder for sealing the cans. Studies in the 1980s attributed the lead from the cans as a factor in the disastrous outcome of the 1845 Franklin expedition to chart and navigate the Northwest Passage. Later studies found this to be false. Increasing mechanization of the canning process, coupled with a huge increase in urban populations across Europe, resulted in a rising demand for canned food. A number of inventions and improvements followed, and by the 1860s smaller machine-made steel cans were possible, and the time to cook food in sealed cans had
Campbell's Soup Cans Warhol drastically simplified the gold medallion that appears on Campbell's Soup cans by replacing the paired allegorical figures with a flat yellow disk. In most variations, the only hint of three-dimensionality came from the shading on the tin lid. Otherwise the image was flat. The works with torn labels are perceived as metaphors of life in the sense that even packaged food must meet its end. They are often described as expressionistic. By 1970, Warhol established the record auction price for a painting by a living American artist with a $60,000 sale of "Big Campbell's Soup Can with Torn Label