I suppose if you were doing a faux fresco you could use tempera paint, but this wouldn't be done using plaster but on paper in the same style. On plaster I don't think the tempera would work.
Acrylics and temperas are water-soluble paints.
Fresco painting.
Two possible reasons: Oil paint on a smooth surface makes for easier painting small details than fresco paint on a wall. A fresco is usually a large-format mural, intended to be seen from a distance.
water-soluble paint
Painting on dry plaster as opposed to painting on wet plaster. Painting on wet plaster is more permanent because the paint is infused with the plaster.
tempera paint
Acrylics and temperas are water-soluble paints.
Fresco painting.
Two possible reasons: Oil paint on a smooth surface makes for easier painting small details than fresco paint on a wall. A fresco is usually a large-format mural, intended to be seen from a distance.
The liquid tempera paint is not waterproof because it is a water base paint.
Tempera paint is made by mixing pigment with a binding agent, which can include egg yolk. The egg yolk acts as a binder that helps the pigment adhere to the painting surface.
water-soluble paint
Painting on dry plaster as opposed to painting on wet plaster. Painting on wet plaster is more permanent because the paint is infused with the plaster.
This is a mural in Santa Maria delle Grazie in Milan, Italy, completed in 1497. Leonardo could have used traditional fresco paint, but preferred to experiment. So he mixed paint of his own invention.
Melozzo da Forlì was hired by Pope Sixtus IV to paint a fresco of Sixtus IV with his three favorite nephews.
Tempera is a low-grade paint and is very thin; oil painting is thicker, which makes it better for a variety of styles. Oil paint also had a slight reflective quality that is prized, whilst tempera is very matte.
Several factors have contributed over time, but the first factor was that Leonardo, the inventor, did not want to use the usual kinds of paint and technique but invented his own, which did not function properly.