This was the final version of Scan done from that very same original color draft.  The skills needed to do the marker version had included an ability to make brush tips do what one wants as well as knowing what precise marker will produce what precise level of dark or lightness.  It was a relatively easy new skill set to take on.  Line and cross hatching were another matter.  I have worked in the stippling technique for so long that I hardly realize that I have internalized the knowledge of very precise working formulas: dot size A + placing those dots in an arrangement density B = value C.  I am almost like a machine when dispening certain densities.  It is just something I can do after all these years.  But with the cross hatching I had to concentrate fully on every bit of line thickness A and density of placement B to get value C.  Again I tested all the various brands of line markers, made flash cards and constructed grid patterns to arrive at would become my final formula. I think the values came out very well. (the photographer who produced this image wondered if it might have been created with a photoshop filter from the previous two versions, for instance) But I was disappointed in some of the transitions between values.  This is a skill one does not pick up in an afternoon.