The Potter's Craft: A Practical Guide for the Studio and Workshop

by Charles Fergus Binns

It is well known that the oxide of iron which imparts to the clay a red color will, if burned in what is known as a "reducing" fire, turn black. This is accomplished by keeping the air supply at the lowest possible point and the effect is heightened by the smoke which is partly absorbed by the clay. This black ware is known as Upchurch pottery from the name of a locality in England where large quantities have been found, but numerous examples occur in Germany and, indeed, wherever the Roman hosts encamped.

A second type of pottery is called Castor ware and consists of a dark clay upon which the decoration is traced in clay of a lighter color. The decoration was applied as a slip or cream and hence was the forerunner of the modern slip painting or pâte-sur-pâte. This ware is well worth a study. The decorations consisted largely of conventional borders and panels but it is specially notable on account of the free use of motives drawn from daily life. One of the commonest scenes depicted is the hunt of hare or stag, the animals and trees being often woven into an almost conventional frieze.

The most valued type of Roman pottery seems to have been the Aretine or Samian ware. This is a bright red color and possesses an extremely thin glaze. A particular clay was evidently used, but all knowledge of its source has been lost.

With the importation of Chinese porcelain by the Dutch the whole trend of pottery manufacture was changed. No longer was black a desirable color, white was seen to be much more delicate and beautiful and henceforth the endeavor of the potter was to produce a ware which should be as nearly like porcelain as possible. The crudeness of the clay kept this ideal from being realized, but various expedients were adopted and gradually better results were obtained.

Throughout the East a type of white pottery was made which, though stimulated by the Chinese example, may have been a relic of the knowledge of the Egyptians. A crude clay was coated with a white preparation, possibly ground quartz, and upon this there were painted conventional designs in sombre colors. A clear glaze covered the whole and imparted to the colors a beautiful quality as of pebbles under water. The nature of the glaze is made evident by the hues assumed by the metallic oxides employed as colorants. Copper oxide affords a turquoise blue, manganese, a wine purple, and iron, a brick red. If the glaze had contained any considerable amount of lead oxide, these colors would have been quite different; copper would have produced green, manganese, dark brown, and iron, yellowish brown. The iron pigment was evidently a clay, sometimes spoken of as Armenian bole. The red color is always in raised masses because if a thin wash had been used the color would have yielded to the action of the glaze.

This ware, commonly called Oriental engobe ware, affords a fruitful study. Effects similar in character were produced by the late Theodore Deck of Paris, but no considerable use of the ancient methods has ever been attempted.

The use of tin and lead in glazing was known to the Arabian and Moorish potters but these ingredients were not abundant in the East. When, however, the Moorish hosts conquered a part of Spain in the twelfth century it was found that both lead and tin were available. The result was the development of the enameled ware known by the generic name Maiolica. Some have maintained that this was first made in Italy but the name is derived from the island of Maiorca from which much of the pottery was exported. The famous Alhambra vase remains as a monument to the skill of the Hispano-Moresque craftsmen, but it was the Italian artists of the Renaissance who brought the enameled wares to perfection. The interest here is artistic and technical rather than historical, but no one can study the work of the period without learning something of Luca della Robbia and Giorgio Andreoli, of Gubbio and Pesaro and Castel Durante.

The use of lead in the glaze proved seductive. It simplified the technical problems and provided a brilliant surface but alas! the colors suffered and one by one they succumbed. The blue of cobalt, however, proved indestructible and so, when the technical knowledge of the South met the traditions borrowed from the Chinese, there was born, in the little town of Delft in Holland, the blue enameled ware which has ever since been known by the name of its native place.

As to the technical details of the production of Delft ware a great deal of information is available. The clay used contained a goodly proportion of lime and this served to hold the enamel in perfect union with the body. The decoration was painted in cobalt blue upon the unburned surface of the enamel. This was, in a measure, courting a difficulty but it is the glory of the craft that a difficulty is cheerfully accepted if in the overcoming there is found success. If the Delft potters had burned their enamel in order to make the painting easy, the world would never have enjoyed the tender tone of blue for which this pottery is famous. By painting the blue color over the powdery enamel, a more perfect union of enamel and color was accomplished than would have been possible by any other means. This fact alone is sufficient to account for the unsatisfactory nature of the modern, so-called, Delft. Difficulties have been avoided rather than met and the success of the early masters has eluded their recent followers.

Much of the pottery made in France in the seventeenth century was inspired by the Italian renaissance. In fact the word faience is due to the avowed intention of the manufacturers of Nevers to copy the enameled pottery of Faenza. Almost the only novelty of the time was the inversion, by the Nevers potters, of the Delft idea. Instead of a white enamel with a blue decoration they used, in part, a blue ground with a decoration in white. It is not known that this variation found acceptance in any other place but in many localities, notably at Rouen, the manufacture of enameled wares was pursued with great success. The only real difference between the wares of Spain, Italy and France, lies in the decorative treatment. Sometimes the emphasis was laid upon lustres, sometimes on blue and white and again upon polychrome painting. In one place there was an extensive use made of pictorial treatment, in another all was conventional. The differences are interesting to a student or a collector but to the craftsman enameled pottery affords but one, though by no means an unimportant, means of expression.