In the absence of other equally durable colors, the colors were applied mainly in the al fresco technique until the 20th century, during which the pigments silicate in a chemical reaction.
Below is this famous Fresco painting of the Sistine Chapel in Rome. Painted by Michelangelo from 1508-1512 “The creation of Adam” Die Erschaffung Adams”
With the still moist plaster base, it remains true to color for a long time. In addition, the Seccotechnik were applied. In the Secco painting, also called dry painting (from the Italian al secco: dry), is a technique in which the colors are applied to the already dry masonry.
In the Middle Ages, especially lime, casein and tempera paints were used, later also oil and silicate paints. Especially in the Romanesque period (about 1000-1200 AD) was the most commonly used in this technique. Even in today’s designs, the paint is almost exclusively al secco to, preferably acrylate inks are used.
For the execution of ceiling frescoes, scaffolding was erected for the plasterers and painters. Work was usually done on stencils or 1: 1 templates of the artist, which were perforated to transfer the contours with colored powder. This work was created by the artist in one day, each of which was prepared with a fresh layer of plaster. If the artist did not make the day’s work, the remaining layer of plaster would have to be knocked off and reapplied the next day.
This relatively cumbersome approach was regarded as a hindrance by many painters and was the reason for numerous attempts to improve the durability with new color mixtures.
An intermediate position is occupied by pictures that were painted on wood or canvas but were intended to be mounted on a ceiling from the outset.