CERAMIC DECORATION—FRANCHET. 645 
way of inlaid ceramic ware. This is the decoration of the Saint 
Porchaire faiences. 
Instead of making large inlaid ornamentations of archaic design 
such as were made in France during the twelfth century, the artists 
of Saint Porchaire ingeniously conceived the idea of filiform inlays, 
offering extraordinary difficulty in the way of execution, entirely 
different in this respect from the faiences of Palissy. 
The faiences of Saint Porchaire are of yellowish color with incrus- 
tations generally colored brown by oxides of iron and manganese, 
and are enameled with a colorless glaze. 
Painting on rough enamel such as was practiced in Italy and later 
in France has one feature of great inconvenience in that since the 
crude enamel is very fragile, the artist can do no retouching. At the 
beginning of the eighteenth century a new sort of technique was 
adopted. The enameled piece was baked at 900° and after this 
baking the design was painted with colors rendered fusible by the 
addition of a flux, which is a glass melting between 600° and 800°. 
The colors prepared by mixing a color producing oxide and a flux 
are apphed over the previously baked covering and are then sub- 
mitted to a special firing at a low temperature, say 650°. These col- 
ors when they become vitrified adhere to the enamel and attain a 
brillant hue. This form of coloring is called decoration with vit- 
rifiable colors. The best-known ancient faiences decorated by this 
process are those of Strasbourg, Lunéville, Saint Armand, and Mar- 
seille. These vitrifiable colors were first applied to the decoration 
of soft porcelain, and afterwards to hard porcelain, on which it was 
almost exclusively used during the nineteenth century at Sevres, 
Berlin, and Meissen. They were abandoned in the art when decora- 
tion under the glaze appeared nearly a century ago. This latter 
form of decoration consists in applying infusible colors reduced to 
an impalpable powder to the unenameled piece, or in other words to 
the paste after it has been baked. This is then covered with a trans- 
parent glaze. All the earthenware which is manufactured to-day for 
table use is decorated by this process. The temperature at which the 
faiences are baked never exceeds 1,070°, so that all the known metallic 
oxides can be used in this decoration. This is not the case in porce- 
lain decoration, which must be subjected to a temperature of 1,400°. 
The number of colors that can resist this high temperature is ex- 
tremely limited; they are the cobalt blues, the chrome greens, the 
roses and reds obtained from the grés (sandstone) of Thiviers, the 
yellow from nickel, the brown from iron and manganese, the gray of 
platinum, and the rose of gold. At this temperature a very beautiful 
yellow may be obtained with uranium oxide, which requires a highly 
oxidizing flame. The straw yellow obtained by the use of titanic 
acid is somewhat pale in tone. 
