What technique did egyptian artists use to paint their relief carvings?

The drawing surface would be delineated using gridded guidelines, snapped onto the wall using string coated in red pigment dust (very much like chalk lines used by modern carpenters). This grid helped the artists properly proportion the figures and lay out the scenes. Scene elements were drafted out using red paint, corrections noted in black paint, and then the painting was executed one color at a time. Even on carved relief, many elements in a scene would be executed only in paint and not cut into the surface. The drawing surface would be delineated using gridded guidelines, snapped onto the wall using string coated in red pigment dust (very much like chalk lines used by modern carpenters). This grid helped the artists properly proportion the figures and lay out the scenes. Scene elements were drafted out using red paint, corrections noted in black paint, and then the painting was executed one color at a time. Even on carved relief, many elements in a scene would be executed only in paint and not cut into the surface.