As my friends know I have been spending a lot of time in the last two years working in Washington, DC on some mural conservations working with an Conservator/artist team to conserve some circa 1880’s decorative murals in an executive branch office building near the White House. With Page Conservation.
About the 1940’s the decorations in a whole series of rooms were painted over and by the time we got to them there were about ten coats of paint on them. So basically the process starts by carefully removing the over-paint while trying to save the original layer. Next, the remaining original mural paint is conserved and stabilized with glue and other materials. Then we re-paint the missing areas in, trying to conserve as much of the original paint as possible. We use reversible materials so our work can always be removed.
This differs from a “restoration” which usually means a recreation of old work as opposed to a “conservation”, which actually means to keep as much original work as possible.
in the following gallery which includes several rooms, you can see the beginning stages (where the ceilings are white), intermediate stages, and the completed stages where the original murals look, well, original! Keep in mind everything you see had been completely painted over.