Read below to learn how frescos are made.
While fresco painting is associated with the Italian Renaissance Masters, the technique has more humble and perhaps accidental beginnings in cave paintings. When pigments were applied to the moist limestone walls of caves, they created a carbonized layer on the cave itself. These images have survived some 35,000 years later. It was during the Italian Renaissance, that fresco painting was perfected and pushed to its most magnificent results.
Essentially, fresco is painting with water-soluble pigments on a freshly applied and still damp plaster base called lime-mortar. In Italian, the term fresco means fresh. As the lime-mortar dries, the pigments bond with the lime that is in the mixture, and creates a thin carbonized layer on the surface. This makes the fresco durable over long periods of time.
The technique of fresco painting, starts with a rigid and somewhat porous base. A layer of rough lime-mortar, or plaster, called arriccio is applied. The mixture consists of coarse sand and lime. An image (called the sinopia) is loosely drawn on the arriccio surface, and then a second layer of smooth lime-mortar (called intonaco) made of finer sand, is applied on top of the drawing.
It is important that the intonaco layer is applied very smoothly, as this is the layer to be painted on. The plaster is fresh (meaning it is still damp) for about eight hours, therefore painting begins right away. With larger images, artists must carefully plan ahead, applying intonaco only for the sections that can be completed within that day. Aptly, these sections are called giornati, or "days" in Italian. Look closely and you may be able to see the giornati lines in large frescoes.
The fresco technique is difficult to master, and takes a skillful hand and endurance to paint major portions of a fresco in a short period of time. But thankfully for hardworking artists and their apprentices, many large scale frescoes were painted and adorn the walls of churches and civic buildings throughout Italy and much of Europe.
Some frescoes you may be familiar with: The Sistine Chapel, located in the Vatican City, Rome, Italy, painted by Michelangelo Buonarroti. The Last Supper, located in the church of Santa Maria delle Grazie in Milan, Italy, painted by Leonardo da Vinci. The Life of Saint Francis located in the Basilica of St. Francis of Assissi, attributed to Giotto and Cimabue. Sadly, in 1996 an earthquake irreparably damaged the upper church, and the frescoes existing since the 1300's were completely lost.