Sometime before 1600, with help from Continental potters and in imitation of Continental wares, British potters were able to make a great advance. It was by using an opaque white glaze on which coloured designs could be painted; a method originating in Italy. This type of pottery, glazed with a composition based on oxide of tin, which was readily available in Britain, is known as delftware from the similar ware made at Delft in Holland; although the latter town did not become connected with pottery-making until some time after British manufacture had started. It is important not to confuse British delftware with Dutch Delftware; a confusion that is not restricted to the verbal sense. For, it was emigrant Dutch potters who came to Britain and started making tin-glazed earthenware in the second half of the 1500's.
The first Dutch potters settled at Norwich, but nothing of their work has been identified positively. The earliest ware of the type is a series of brightly coloured jugs, named after the village in Kent where one was once kept in the church, West Mailing, near Maidstone. One of these 'Malling' jugs has a silver mount dated 1550, and others bear later dates between then and 1600. Queen Elizabeth I was petitioned by two Dutch potters, named Jaspar Andries and Jacob Janson, to allow them to settle and work in Britain, and it is believed that Janson set up a pottery in London in 1571. An early British dated piece of pottery now in the London Museum is a dish painted in colours with what appears to be the Tower of London, the date 1600, and an inscription reading 'The Rose is Red The Leaves are Grene God Save Elizabeth Our Queene'. It seems probable that this is of London manufacture but the colours used and style of painting are very like those on ware made on the Continent at the time.
A further surviving group of wares is dated about 1630, and consists of a number of mugs bearing British names and of shapes unlike current foreign types. Whereas these and earlier wares show, if anything, an Italian influence in the style and colouring of their decoration, the productions that followed were copied as closely as possible from Chinese porcelain; which by 1640-50 was coming to Britain in sufficient quantity to be a serious rival. Not only was Oriental porcelain being brought to Britain, but the other countries of Europe also imported it and their potteries in turn set out to imitate the newcomer. It is clear that with pottery being made in Britain by Dutch potters copying Chinese originals and the same subjects being copied by the Dutch in their own country, it is not an easy matter to distinguish between the two wares. No British wares are marked, and it is agreed that only those of the 1600's of certain types and bearing British names or inscriptions can be accepted reasonably as originating in London. Among such pieces are a number of wine-bottles with dates from 1637 to 1672, and painted also with the names of wines: 'Claret', 'Sack' and 'Whit' (White). On these the painting is very sparse and the white body is often tinged with pale pink; a feature of tin-glaze. Allied to these bottles are a number of dishes, candlesticks, vases and other pieces, completely unpainted but of which many show the same slightly pink glaze.
Also with this characteristic are pieces painted with the coats-of-arms of London companies, in particular the Company of Apothecaries with their motto 'Opiferque Per Orbem Dicor' found on shaped flat pill-slabs. During the 1600's were produced a great number of large dishes, called sometimes 'blue-dash' chargers from their borders being painted with a series of dashes in blue. They are skilfully painted in colours, and the subjects on them vary from Adam and Eve to scenes of the reigning monarch and his family. Many are dated, but there is ground for viewing some of the dates with suspicion; one dish showing Charles I and his family is dated 1653 although he had died eight years earlier, and another of'1614' is of a type considered to have been made not less than thirty years after. No reason has yet been found to account for these discrepancies. Until about 1660 London delftware was made at Aldgate or Southwark, but shortly afterwards potteries were opened in Lambeth, which soon expanded and became the most important in Britain. By this time some of the Southwark potters had started a works at Brislington, near Bristol, and within a further period there were potteries operating in Bristol itself and in Wincanton, Somerset, and by 1710 in Liverpool. A group of Lambeth potters was working in Glasgow in 1748, and potteries were operating in Ireland at Dublin from about 1737, and Limerick from 1762.
These various potteries not only owed their beginnings to the efforts and skill of men from their fellow-manufactories, but these very men did much the same work in their new homes as they had done in their old. The variations in clays, glazes and colours between one factory and another are slight, and the wares must often be apportioned to each factory on other evidence. Excavations made on the site of former potteries, and pieces that have remained in the hands of descendants of known potters and painters, and similarly documented specimens give a more reliable picture. Unfortunately, there is still not enough accumulated evidence to make certain identification possible in the majority of instances. All the English delftware potteries in the 1700's copied principally Chinese imported ware, with a marked predominance of painting in blue. A quantity of commemorative pieces was made, and includes many recording coronations. Other inscribed pieces bear initials and dates, but rarely, if ever, was anything resembling a factory mark employed. Tin-glazed earthenware was enormously popular in its day as can be seen from the great number of surviving specimens, but towards the end of the 1700's it succumbed to the superior merit and lower cost of creamware.