No, No, No, sorry to have to say this but a Kilner jar and a Ball jar are two completely different jars. John Kilner (1792-1857) invented the Kilner jar along with his associates. He later founded the John Kilner & Co glass company in 1842 that produced this jar. Although enjoying commercial success, rival glass manufacturers were quick to create alternatives - and the Kilner family business (by then called Kilner Brothers Ltd) went bankrupt in 1937. The patents and trademarks of the Kilner Jar were sold to the United Glass Bottle Company in the same year, where more modern Kilner jars are still being produced today. John Kilner was the great-great-great-great Grandfather of famous motoring journalist, Jeremy Clarkson. A Mason jar is a glass jar used in canning to preserve food. They were invented and patented by John L. Mason in 1858. They are also called Ball jars, after Ball Corp., a popular and early manufacturer of the jars; fruit jars because they are often used to store fruit; or generically glass canning jars. While largely supplanted by other methods for commercial mass-production, they are still commonly used in home canning. In modern usage, the terms often refer specifically to jars featuring a two-piece cover: An inner, flat, metal or glass lid, covered by a screw-on ring. The ring holds the lid in place during the canning process, which creates a partial vacuum, sealing the lid until opened. The lids are sold separately so that the jars and rings can be reused. Mason jars are made of soda-lime glass, and come in a variety of sizes including pint, quart, half-gallon, and cup sizes, as well as in wide-mouth and regular mouth shapes. The most common US brands of Mason jars are Ball and Kerr, both brand names now part of the Jarden corporation.