Shoppers can buy Pyrex lids directly from Pyrex.com. Amazon.com and other retailers, such as Walmart.com, also sell them. As of 2015, most Pyrex cookware and storage container lids for sale are plastic, but some of the classic glass lids are still available.
The Pyrex brand was introduced in 1915 by Corning Glass, which then made lantern glass for railroads. When the wife of one of Corning's scientists asked her husband for some heat-resistant glass to replace a casserole dish, she found that a cake baked evenly in it and that the glass was easy to clean. This led to the creation of the first product in the Pyrex kitchenware line, the casserole dish.