294 15·No Ceramics Age? ably all specimens of this production sustained some distortion during firing which led eventually to the abandonment of this technique.Likewise,French soft-paste porcelain (with high lime and low clay content)were difficult to form and fire. For the interested reader some recipes for porcelain and glazes are listed below.The quantities are given in mass percent. White porcelain (for casting bodies) Kaolin 46% Silica 34.2% Potassium feldspar 19.8% Add Sodium Carbonate 0.4% Firing temperature 1285-1325°C Shrinkage 11.5% White/light-gray porcelain(for throwing bodies) Kaolin 40% Silica 25% Potassium feldspar 25% Ball clay (Kentucky #4) 7% Bentonite (volcanic ash clay) 3% Firing temperature 1260-1325°C Shrinkage 15% Clear semi-mat glaze Feldspar 58% Silica 12.5% Whiting (natural CaCo3) 12.5% Kaolin 11% Zinc oxide 6% Add:C.M.C.2 1 tsp. Firing temperature: 1170-1250°C 15.3.Shaping and Decoration of Pottery One of the earliest methods for shaping clay included pressing the clay into a basket which was eventually consumed by the fire. Other techniques utilized paddling clay over the exterior of a mold pot to form the base,whereby the upper portion was formed with a series of coils laid layer upon layer.Also,hand-modelling was frequently practiced.The potter's wheel is,in contrast,a rel- Adapted from J.Chappell,Clay and Glazes (see Suggestions for Further Study). 2Carboxymethyl cellulose (acts as thickener and binder).ably all specimens of this production sustained some distortion during firing which led eventually to the abandonment of this technique. Likewise, French soft-paste porcelain (with high lime and low clay content) were difficult to form and fire. For the interested reader some recipes for porcelain and glazes are listed below.1 The quantities are given in mass percent. White porcelain (for casting bodies) Kaolin 46% Silica 34.2% Potassium feldspar 19.8% Add Sodium Carbonate 0.4% Firing temperature 1285–1325°C Shrinkage 11.5% White/light-gray porcelain (for throwing bodies) Kaolin 40% Silica 25% Potassium feldspar 25% Ball clay (Kentucky #4) 7% Bentonite (volcanic ash clay) 3% Firing temperature 1260–1325°C Shrinkage 15% Clear semi-mat glaze Feldspar 58% Silica 12.5% Whiting (natural CaCo3) 12.5% Kaolin 11% Zinc oxide 6% Add: C.M.C.2 1 tsp. Firing temperature: 1170–1250°C One of the earliest methods for shaping clay included pressing the clay into a basket which was eventually consumed by the fire. Other techniques utilized paddling clay over the exterior of a mold pot to form the base, whereby the upper portion was formed with a series of coils laid layer upon layer. Also, hand-modelling was frequently practiced. The potter’s wheel is, in contrast, a rel- 294 15 • No Ceramics Age? 1Adapted from J. Chappell, Clay and Glazes (see Suggestions for Further Study). 2Carboxymethyl cellulose (acts as thickener and binder). 15.3 • Shaping and Decoration of Pottery