Whatever the technique used to decorate under glaze, the colors must be permanently attached to the support with a thin layer of the cristallina, gloss or opaque. The cristallina is the cover vitreous and transparent (colorless or colored), which apply on an object already fired, said biscuit, used mainly on the clay, which does not alter the color of the cristallina.

To apply the cristallina, it surely be essential to immerse the object in a container, in which, it has been melted and sifted with a fine meshed sieve. If it doesn't have an adequate amount of cristallina, it can be sprayed with an airbrush gun. The thickness of the cristallina should be about half a millimeter. Now, the workpiece must be clean from the cristallina or glaze in the points in which rests on the plates, so that the glaze by melting does not stick, this operation must be done with a scraper. After this the item is put into the kiln and fired at the appropriate degree for the cristallina used.

Perhaps, not everyone knows that the various objects, you can't fire at random, but requires the exact process in order that to not ruin their surface and achieve an optimal firing. It's important to load the kiln in several layers, in this way saving energy and space, however, we need to remember that during the firing of the glaze, the pieces have to be place at a distance at least 5 mm. Electric kiln, for its ease of use and instalment, is fairly common in the workshops and studios.