THE PRODUCTS OF CLAY AND FIRE 



on account of the action of the glaze-firing that follows, 

 are practically eliminated in the process of overglaze 

 decoration. The degree of heat necessary to fix the 

 colors applied over the glaze is much less than that of 

 the glaze-kiln, and the effect upon the colors very 

 slight, and so well understood, that the decorator has 

 practically unlimited scope both as to color scheme 

 and design. Real works of art, comparing favorably 

 with those painted on canvas, with every degree of 

 delicacy of tint, have been made, and are still being 

 made, in great numbers, on china ware. The colors 

 are more permanently fixed than those on canvas, or 

 any other material in fact, are practically inde- 

 structible except by breakage of the ware. With dishes 

 in daily use, to be sure, the colors do eventually lose 

 their brilliancy, and finally wear off; but this is due 

 solely to constant and hard usage. Potters, however, 

 prefer the underglaze decoration as a rule, claiming 

 that the depth of tone in pieces thus painted more 

 than offsets the variety of colors. But they find a com- 

 bination of the two processes very useful, particularly 

 in expensive pieces where the underglaze design has 

 not come out well in all places. Where such defects 

 are found the pieces can be touched up after the glost- 

 firing, fired in the enamel kiln, and made perfect. 



The metals supply most of the colors used in china 

 decoration, although there are some earths used for 

 certain purposes. Not all the metallic colors, however, 

 will withstand the heat of the glost-oven; and such 

 colors can only be used for overglaze decoration. 

 Gold and copper give two such colors. The gold is 



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