 Occasionally there can be difficulties telling the two apart, usually with blue and white pieces.The quality of the porcelain is not the highest, especially after 1770, but even the less polished pieces have "the appealling simplicity of folk art", and the high proportion of commemorative pieces, inscribed for people, places or occasions, add to their interest.Many such documentary pieces are dated which, together with the wasters excavated at the site in 1902 and 1967, has helped to build up a good picture of the factory's products.