Mocha
Ceramic mocha is a traditional decorative technique that relies on the physical and chemical properties of ceramic suspensions and alkaline solutions to create dendritic, organic and random patterns on the surface of the piece.
The process begins with the application of a fresh engobe (a mixture of clay and water) on the surface of the raw or partially dried piece. While the engobe maintains a high moisture content, an alkaline solution mixed with a pigment (e.g., metal oxides or ceramic colorants) is carefully added. Upon contact with the wet engobe, the alkaline solution generates a different surface tension and promotes the "migration" of the pigment, which branches by capillarity, producing patterns reminiscent of agate veins.
The particularity of the mocha lies in the spontaneity and unpredictability of its patterns: each application generates a unique and unrepeatable design, difficult to control completely, which gives the piece a marked artisanal and aesthetic value. The variety of results obtained with mocha depends on numerous factors: the composition of the engobe, the concentration of the alkali, the fluidity of the pigment, the ambient humidity, the method of application and even the inclination or movement of the piece.Interesting Fact
The ceramic mocha technique was inspired by the appearance of lichens and mosses that formed similar patterns on logs and rocks, and was developed in England during the 18th century. Its name "mocha" alludes to the veins of mocha agate.Helpful Tip
Try different concentrations of alkaline solution and different types of engobes. A more liquid or drier engobe, or a more or less concentrated alkali, will modify the speed and intensity of propagation, adjusting the level of detail and contrast in the patterns.
