Materials used in wall painting

Lime

It is obtained by firing certain grades of limestone consisting mainly of calcium carbonate and with a lower or higher content of oxides of iron, manganese, marl or clay, quartz sand, graphite, bitumen and charcoal.
The amount and mix of these components depends on the origin of the limestone. The higher grade of limestone is obtained by firing white marble consisting only of crystalline grains of
calcite.

Properties of quicklime and slaked lime

1. It is alkaline in nature. Has a negative effect on plants and some minerals. It decomposes and saponifies fats. As a result, oil painting decomposes, as long as it was painted on plaster that has not dried well.
2. Lime dough has a high binding force, but it cannot be used alone for mortar, as it becomes very crumbly as it dries. To prevent this, fillers such as sand are used for lime mortar.
3. Burnt lime should not be stored with access to air, as it pulls moisture from it and self-extinguishes.
4. With casein, oil, sugar, egg white and animal glue, lime forms insoluble compounds.