Joséphine Bowes was a pioneer collector of tin-glazed earthenware, and formed a large collection of what is called 'faience' in France, 'Delftware' in Holland and 'maiolica' in Italy.
Their common characteristic is that they are covered in a layer of glaze with tin oxide in it, that turns white in the kiln to imitate the white colour of porcelain. Before firing, it can be painted with powdered metallic oxides to give it coloured decoration. The Bowes Museum has about two hundred pieces of Italian maiolica, including drug jars and plaques, as well as a rare potter's sample plate from Padua dated 1577; over one thousand pieces of French and German faience from the 17th and 18th centuries (probably the best collection in Britain outside the Victoria and Albert Museum) and over five hundred pieces of Dutch Delftware, many imitating blue and white Chinese porcelain (again probably the best collection in Britain outside the Victoria and Albert Museum). In addition, there are some interesting examples of native French pottery by village craftsmen, and an extensive collection of German stoneware of the 16th, 17th and 18th centuries.