Magic sometimes happens. I was drawing the spire of Rouen Cathedral following a downpour of rain when a monk in a white habit appeared almost miraculously walking towards me. The reflection in the wet road made it look as if he was walking on water. I made very quick drawings and when I got back to London a couple of days later, started on the drawing proper in my studio.
The process I used was, in effect, drawing in reverse.
I first cover a high quality paper with three or four layers of very dense graphite. I then begin erasing, gradually removing the graphite and work my way back to the white of the paper. The paper has to be good in order to resist the constant rubbing out.
I can’t make many of these because the process creates a lot of graphite dust and I am wary of breathing too much of it. I used this same technique for the two drawings of the Dales Landscapes and the drawing London. They are all on this website.