What ancient mural painting technique involves applying pigment mixed with water directly onto a freshly laid layer of wet lime plaster, allowing the color to chemically bond with the wall as it dries?

💡 Explanation:

Fresco (specifically 'Buon Fresco' or 'true' fresco) is the technique of painting on wet plaster. As the plaster dries, the pigments become permanently fixed and integrated into the wall surface. This method was famously used in the ceilings and walls of the Sistine Chapel.