CLAYS OF NEW YOKK 777 



DECOEATIVE TILE 



WMle many of the tile mentioiied under tlie previous liead could 

 be classed under this one, at the same time it applies more directly 

 to those tile which are not only glazed, but also often ornamented 

 with raised designs. They are used to a large degree for wains- 

 cotting, mantels, soda water fountains, etc. 



There is but one factory in this state engaged in the manu- 

 facture of glazed tile ; that is the Tarrytown porcelain tile co.'s at 

 Tarrytown, 



Glazed tile are made by the dry press process. The color of the 

 body is generally white. The relief of the surface is often very 

 prominent, and over this there is usually a heavy coating of colored 

 glaze, the variation of the glaze in depth being depended on to 

 bring out the decorative effect, as those portions over which the 

 glaze is thickest appear the darkest. Glazed tile should show the 

 same freedom from warping in drying and burning as those pre- 

 viously described; and in addition the glaze should be free from 

 cracks or crazes, pin holes and bubbles. ' 



Sometimes colorless glazes are used, at others a tin glaze imparts 

 a white opaque covering to the tile. For other colors the oxids of 

 cobalt, nickel, copper, chromium, manganese, iron or uranium are 

 used according to the colors desired. 



Methods of decoration. ' 



These have already been referred to in part under the descrip- 

 tion of the methods of manufacture. 



While the use of natural clays permits the production of a con- 

 siderable range of colors, nevertheless these fall far short of the 

 ambition of the ceramic chemist and the demands of the architect. 



As the use of artificial coloring materials is often expensive, the 

 color decoration is applied to the surface of the ware only, instead 

 of allowing the design to extend through the body. 



