9. Producing faience

The clay used for faience consists of quartz, feldspar, clay and kaolin. This clay is made in the same way as porcelain clay, just as products in faience are moulded or thrown in similar ways to porcelain.

The difference between porcelain and faience lies in the firing sequence, and consequently in the finished appearance of faience. Faience is fired at the highest temperature, and achieves its final strength, at the first firing, which takes place in an oxidizing atmosphere at about 1200°C. As a result of the air content in the body and oxidizing firing, faience products are slightly yellowish and not translucent.

After the first or biscuit firing, the faience is ready to be decorated, glazed and then glaze-fired at about 1100°C. The faience glaze is a mixture of feldspar, quartz, lead frit and boron frit (frit is crushed glass), which is ground to an emulsion with water, and after standardization can be used for glazing.

The glaze used for faience is not as thick-flowing as that used for porcelain, and has practically no air bubbles. Since the glaze-firing temperature is lower, there is a wider palette of colours available than for underglaze and overglaze decorated porcelain. This, together with the clear glaze and opaque, ivory-coloured body, gives faience its distinctive character.

Faience can be decorated under the glaze, either by screen-printing or hand painting, or by a combination of the two.

Selected items of Ole and Ursula are in faience.