The decoration is effected on the previously enamelled biscuit. In the best craft shops it is exclusively carried by hand without using any approximate and rushed techniques, such as spraying and printing. The colour is applied onto the untreated enamel and perfectly adheres to the enamelled surface while baking, because when the enamel melts, the colour sticks to it irreversibly.
The colour preparation is very ancient. It was accomplished by milling the colours in a mortar with a pestle adding water until a paste is obtained. This is diluted with water and filtered through a very fine silk sieve.
When applying the colours, it is necessary not to exceed with the colour; they may be applied by overlapping layers, from the lightest to the darkest, the technique is similar to watercolour except that it is not possible to correct mistakes or make changes.
The decoration is made the on raw enamel by using a simple pencil or else aniline or red lead colours diluted in water. These substances will burn during baking without leaving any traces. The dusting technique is widespread in several craft shops producing extremely elaborated works.
This consists of a manifold paper with a drawing traced with a series of needle holes one after the other. The dusting is laid on the surface to be decorated and is slightly plugged with a cloth, which is made of a silk stocking or a normal piece of loosely spun cotton material filled with coal.
Through the holes realized with the dusting technique, the coal will stick to the enamel surface faithfully reproducing the traces and the proportions of the drawing.
Majolica painting has always been considered as being the most difficult and complex pictorial technique among the various arts and crafts because the colours and the tones used do not correspond to the colour appearing after baking, and moreover, they can be mixed together to obtain combined shades without knowing for certain the final result. Unlike other techniques, the decoration presents some disadvantages. Indeed, the surfaces to be decorated are spherical rather than flat and due to the friability of the enamel, it is difficult to apply colours with the adequate intensity on this type of dry and dusty support.