Color Cement Handicraft

by Pedro J. Lemos; Reta A. Lemos

SGRAFFITO is the name applied to the incised ware of the Italians, and used by them from a very early period dating as far back as the twelfth and thirteenth centuries. The ware was made by covering the clay body with a layer of slip of another color, and this was then scratched through with a tool showing the color of the ware beneath against the superimposed surface, after which it was fired. This process has been used from the most primitive times, but it remained for the Italians of the fifteenth century to dignify it as an art.

COLOR CEMENT SGRAFFITO is produced with a layer of cement and color being used instead of colored clay and the cement is hardened without firing, water only being used to finish the surface to a durable quality.

THERE ARE TWO WAYS to produce a sgraffito surface on a tile and these are, the glazed surface and the dull surface tile. No mold is needed for the design as a sgraffito design must necessarily be a freehand production, though molds may be used for duplicating the sgraffito effect after the original one has been made, if no undercut edges are left.

TO PRODUCE A SGRAFFITO TILE, the retaining bars are set to give the desired shape and dimensions, after which the space is filled with a half inch layer of concrete, either of sand and cement mixture or of gravel and cement. When this layer has dried so that the top section is moist but firm in surface, a thin layer of color and cement should be poured onto the cement so that it forms a thin layer not more than an eighth of an inch thick.

TO SMOOTH THE LAYERS after the color has been poured in, shake the glass or table or whatever surface the mold is resting upon and if this is done gently it will cause the color to become level and even in surface finish.

TO CAUSE TILES TO BE EQUAL IN THICKNESS the surface of the glass or table upon which the mold rests should be level when the cement is poured in. Otherwise the tile when finished will be found to be thicker on one side than on the other. A glass or pan of water or a spirit level will quickly show whether or not the surface is level.

AFTER THE FIRST COLOR LAYER IS POURED into the mold it is permitted to stand just long enough to settle firmly and then a second layer of another color is poured over the first layer so that it also forms a thin layer of even color. This second layer should be even thinner than the first. A layer one-sixteenth of an inch is a good dimension to plan on, though these dimensions need not be accurately adhered to. If the first layer is permitted to dry too long before the second layer is added the result will be that as the finished sgraffito tile is drying it will split in layers, the split coming between the layers of colors that were permitted to dry too long.

A THIRD LAYER OF COLOR may be added over the second layer if the design being planned calls for three divisions of colors. These layers are to respond to the next step in the process, which is to expose portions of each layer by tooling the surfaces so as to produce different colors at the same time that the different depths are produced.

THE TOP LAYER WILL DRY WITH A SMOOTH SURFACE which will produce a sgraffito tile with a glazed or partly polished surface while the other layers will have a surface with dull texture.

TO PRODUCE A TILE WITH A DULL SURFACE throughout, the pouring stages should be reversed in their steps. That is, the color that is to be the top surface should be poured first and the other colors in their proper relation, the last layer being the cement and sand or other concrete mixture. This will result in the layer first poured in coming next to the glass, having a dull finish when it is released from the mold.