As a readily available by-product of modern pork production, lard had been cheaper than most vegetable oils, and it was common in many people's diet until the industrial revolution made vegetable oils more common and more affordable. Vegetable shortenings were developed in the early 1900s, which made it possible to use vegetable-based fats in baking and in other uses where solid fats were called for. Upton Sinclair's novel The Jungle, though fictional, portrayed men falling into rendering vats and being sold as lard, and it generated negative publicity.