Throughout history, man has been responsible for developing different techniques conducive to the development of domestic artifacts. These creations, popular thousands of years ago, remain to this day, but as an interesting decorative element. One of these activities is pottery, the art of designing and creating vessels from clay or clay; It was born in the Upper Paleolithic, in small representations of maternal deities, such as Venusscored by Dolní Věstonice. Likewise, the oldest known vessel comes from the Jōmon period - one of the prehistoric times of Japan - of at least 10,000 years. It should be noted that, for some ceramologists such as Emili Francés Sempere, it is necessary to distinguish ceramics, which combines both sculpture and painting, from pottery, which is characterized by a more popular and practical tone.
Even so, the materials used in both practices are characterized by being quite similar. In pottery, for example, a mixture of water and clay, which has an almost liquid consistency, is used to join pieces previously made by hand or for decorative purposes, which is called slip. With the evolution of the techniques used in pottery, for the preparation of this mixture, a chemical process called levigation was implemented, which basically consists in the separation of mixtures, that is, indicating a dispersion of particles; This is done in order to make the preparation much more resistant and durable. To achieve this, other components are added, such as tannic acid, sodium carbonate or soluble sodium silicate.
In the ceramics industry it is considered of great importance that the slip does not contain lumps, in addition to that its density must be adequate to the creation; For this reason, a series of processes are put into practice in which it is sought to accurately measure it. In some areas, in the same way, it is quite common that all the residues that are found at the bottom of the vessel and in which the potter puts his hands are called slip, to reduce friction when molding the sculptures.
