Mina'i ware in the context of "Fritware"

Persian pottery or Iranian pottery is the pottery made by the artists of Persia (Iran) and its history goes back to early Neolithic Age (7th millennium BCE). Agriculture gave rise to the baking of clay, and the making of utensils by the people of Iran. Through the centuries, Persian potters have responded to the demands and changes brought by political turmoil by adopting and refining newly introduced forms and blending them into their own culture. This innovative attitude has survived through time and influenced many other cultures around the world.

There were two types of earthenware that were prevalent in Iran around 4,000 BC: red and black ceramics that were simplistic in their decorative style. As the art expanded, earthenware incorporated geometric designs which resulted in a more developed decorative style. This increasingly complex style was accompanied by the creation of a wider variety of the kinds of pottery that were made.

Underglaze is a method of decorating pottery in which painted decoration is applied to the surface before it is covered with a transparent ceramic glaze and fired in a kiln. Because the glaze subsequently covers it, such decoration is completely durable, and it also allows the production of pottery with a surface that has a uniform sheen. Underglaze decoration uses pigments derived from oxides which fuse with the glaze when the piece is fired in a kiln. It is also a cheaper method, as only a single firing is needed, whereas overglaze decoration requires a second firing at a lower temperature.

Many historical styles, for example Persian mina'i ware, Japanese Imari ware, Chinese doucai and wucai, combine the two types of decoration. In such cases the first firing for the body, underglaze decoration and glaze is followed by the second firing after the overglaze enamels have been applied. However, because the main or glost firing is at a higher temperature than used in overglaze decoration, the range of colours available in underglaze is more limited, and was especially so for porcelain in historical times, as the firing temperature required for the porcelain body is especially high. Early porcelain was largely restricted to underglaze blue, and a range of browns and reds. Other colours turned black in a high-temperature firing.

Overglaze decoration, overglaze enamelling, or on-glaze decoration, is a method of decorating pottery, most often porcelain, where the coloured decoration is applied on top of the already fired and glazed surface, and then fixed in a second firing at a relatively low temperature, often in a muffle kiln. It is often described as producing "enamelled" decoration. The colours fuse onto the glaze, so the decoration becomes durable. This decorative firing is usually done at a lower temperature which allows for a more varied and vivid palette of colours, using pigments which will not colour correctly at the high temperature necessary to fire the porcelain body. Historically, a relatively narrow range of colours could be achieved with underglaze decoration, where the coloured pattern is applied before glazing, notably the cobalt blue of blue and white porcelain.

Many historical styles, for example mina'i ware, Imari ware, Chinese doucai, and wucai, combine the two types of decoration. In such cases the first firing for the body, underglaze decoration and glaze is followed by the second firing after the overglaze enamels have been applied.