Manuscripts inscribed on parchment in ancient Egypt were written on both sides (recto--front, and verso--back). These pages, often erased and reused, were called palimpsests.
This is a printer's word for the evidence that an original work of art has been altered. Often the paint with which the artist has covered a mistake or a change of mind will become transparent. The original work will then become visible through the final composition. This creeping through of an image is sometimes compared to a palimpsest.
In Renaissance Italy frescoes--the word means fresh in Italian--were created by painting on damp lime plaster. the dampness and the lime created an element that, as the wall dried, held the paint and color magnificently. All colors are not lime-proof, so the colors an artist could use were limited, but those that the wall held are clear and luminous. DaVinci's Last Super is a fresco.
A painting method used in mural painting, usually applied to dry walls. Tempera's advantage is that it produces clear, pure colors. It is also used in combination with oil paint.