You're Quite right, obviously the cartouche was painted after the application of the plaster wash and even more obviously the plaster wash was applied post block installation.
I tend toward the white wash being ancient and applied soon after block installation. At or around the same time as the adjacent block filler. Same as the filler material, just less viscous, watered down.
Both the wash and block filler material appear to show a gloss finish with specular highlights under direct flash illumination.
Tura limestone is Matt white.
It's also interesting that only the cartouche block is almost totally wash covered in its entirety. (There's an unpainted section at the bottom left). The blocks either side only being partially white washed.
Edited 2 time(s). Last edit at 21-Jun-16 15:36 by Jon Ellison.