Can I Get a Witness?

  The next step in the gilding process is to apply a very thin wash of red clay.  This is same concept we do in woodworking when we're using a smooth plane to finish a surface.  Instead of using light pencil marks like you would on wood, in gilding you use a thin layer of red clay.  I'll  sand the gesso to create the smoothest possible finish for the clay, when the witness coat is gone then that's my cue that every portion of the frame has been sanded.  The only place I won't sand is over the carving.  The technique there is to use a damp cloth to smooth the carving.  The picture below shows the pattern for the carve better.