Identify Delft pottery by looking at the markings. For instance, Royal Delft vases made after 1876 have a De Porcelain Fles factory mark and a maker's mark. The maker's mark is a JT, underneath which reads the word Delft accompanied by the date code, artist's initials and style number.
Another way to identify Delft pottery is to look at the date stamp. From 1879 on, the date stamp is a series of letters. The period between 1879 and 1904 uses A through Z, with each letter being a year. 1905 to 1930 uses AA through ZZ. The next 75 years use BA through BZ, CA through CZ and DA to DZ up until 2006.
Originally produced in Delft, Holland, Delftware was a response to Ming dynasty porcelain brought over from China in the 1600s. One of Delftware's main features is its distinct blue and white coloration, made when manganese purple is combined with a blue underglaze. Another influence on the pottery was French motifs. At the end of the 1600s, companies began producing Delftware in both Ireland and England, known as English Delft. Another type of this pottery was Black Delft, produced in Holland with a black base and gilded edges.