If the painting was to be done over an existing fresco, the surface would be roughened to provide better adhesion.
On the day of painting, the intonaco, a thinner, smooth layer of fine plaster was added to the amount of wall that was expected to be completed that day, sometimes matching the contours of the figures or the landscape, but more often just starting from the top of the composition.
By measuring the argon content of many rocks that contain potassium, scientists can calculate the age of the rock.
Fresco (plural frescos or frescoes) is a technique of mural painting executed upon freshly-laid, or wet lime plaster.
This means it is the radiation responsible for ionising molecules. Small doses of radiation over a long period of time can cause the cells to multiply. Background radiation comes from the soil, rocks, the air, water, plants, building materials and food.
If this happens in our body, the cells may die or they may undergo a change called a mutation. Some radiation is due to cosmic rays from outer space.
Michelangelo used this technique as part of his trademark 'outlining' of his central figures within his frescoes.
Buon fresco pigment is mixed with room temperature water and is used on a thin layer of wet, fresh plaster, called the intonaco (after the Italian word for plaster).
However, fortunately, our body can withstand low level radiation without ill effects because it is able to repair any damage.
Gamma rays are capable of passing deep inside the body and damage cells on their travels. The idea is to aim accurately at these cells with the correct strength.
If mistakes have been made, it may also be necessary to remove the whole intonaco for that area—or to change them later, a secco.
An indispensable component of this process is the carbonatation of the lime, which fixes the colour in the plaster ensuring durability of the fresco for future generations.