Treacleware, or ‘Rockingham’ brown-glazed ware, includes a wide number of variations. They are earthenwares that have a brown glaze that is generally fluid and translucent to some degree. The variations in treacleware include two-tone, dipped, splashed, amber, Measham ware (bargeware or canal boat ware) and many others.
The Swinton factory, Yorkshire, gave the name Rockingham to their refined brown-glazed earthenwares to honour their patron and landlord, Charles Watson Wentworth the 2nd Marquis of Rockingham. This ‘Rockingham’ ware gained popularity with the upper classes and royalty, so that prices soared. Other potters copied the name to share in the craze. The Swinton Works did not invent Rockingham ware (treacleware), they instead refined it and re-named it.
Iron oxide and manganese dioxide have been used to produce brown and purple-brown glazes in many countries and for many centuries. Most British treacleware was made from the late C18th to the early C20th but it’s origins go back much further. Early types include C16th/C17th Cistercian ware and C17th/C18th Midlands blackware etc..
American treacleware or Rockingham and Flint enamel wares are often based on English originals but have a distinctive character of their own. The Bennington, Vermont factories are the most famous in the USA but other centres produced it too.