The color range in unglazed tiles are limited to the natural colors of the clay, ranging from a light sand to a red brick.
White lead, flint, china stone and china clay were ground to form a glaze. a clear glaze brought out the natural body color and might be applied over any colored decoration. glazed tiles are decorated with natural and artificially colors. palette of colors consists of glaze and underglaze colors. The first glazes were blue in color and were made from copper. also turquoise and light green glaze were popular colors. Ground metal oxide could be added to give different colors.
ENCAUSTIC OR INLAID:
This method was to fill the matrix of a stamped tile with white pipe clay before it was glazed and fired. The two sections fusing during firing.
Artistic tiles in such colors as yellow, blue, brown, black, turquoise, green and white were cut and carved into small pieces according to a previously prepared pattern, these pieces were placed close together and liquid plaster poured over to fill in all the opening and gaps. After the plaster dried and hardened, a large single piece tile panel had been created, which was then plastered onto the required wall of the building.
The artist painted freely onto a plain surface tile. The glaze was one centimeter thick, with hand-painted decorations of flowers, plants, geometric designs, birds and human beings. A design could also be copied from an original sketch by ‘pouncing’. alternatively a tile could be transfer printed and colored by hand.
CARVED AND MODELED TILES:
Each piece is individually carved in relief or modeled in clay, the pattern could be engraved in outline on the surface of the tile or the design carved in relief or counter-relief on a wood-block which was then pressed into the artistic tile. sometimes painted to emphasize the three-dimensional appearance of the work.
An early form of decoration, the tile body is covered with coats of slip that is scratched off to produce the design.
The metallic luster of glazed ceramics is a very special type of decoration. It can be red, brown, ochre yellow or green in scattered light and shows, in specular reflection, colored metallic reflections (blue, yellow, orange, rose…). Metallic copper and silver colloids suspended in glazes compose luster decoration.
Slip is trailed onto the surface of the tile to make raised lines separating the areas where different color is wanted. colored glazes were then applied. This technique was used for art nouveau tiles.
A copper plate was engraved with a design, this would be covered in color, the excess removed leaving the color only in the engraved parts. A tissue paper was pressed onto the plate, and placed color side down onto the tile. Then removed, and the color transferred to the artistic tile. This method was quicker, and therefore cheaper than hand painting.