Pontypool japan is a name given to the process of japanning with the use of an oil varnish and heat, which is credited to Thomas Allgood of Pontypool. In the late 17th century, during his search for a corrosion-resistant coating for iron, he developed a recipe that included asphaltum, linseed oil and burnt umber. Once applied to metal and heated the coating turned black and was extremely tough and durable.
Pontypool is in a steep valley in South Wales, surrounded by coal and iron working. The iron used was produced by the furnaces of Blaenavon to the north, and most of the "Pontypool ware" was actually produced in nearby Usk or Newport, at the southern end of the valley.