Additive vs subtractive portrait sketches

 "Jane"- 12x12 charcoal

    The two drawing methods of additive (starting with a blank page) or subtractive (starting with a toned page) lend to many beneficial results that I find should both be praised and contemplated when starting a quick sketch session (anything under 2 hours).
   Additive: Lends more to work in line and usually keeping the drawing light and airy. If I find a line wrongly placed I can (in charcoal) smudge it out and work into tone of the drawing. The lightness seems to match a feminine portrait.

 "Chuck"-12x12 charcoal

   Subtractive: Lends more to working in mass and planes. It is good to get a predominately busy drawing moving more quickly from the start and often lends a sense of atmosphere to set the head off from the ground. Because my working backwards of removing light areas from the midground tone is a but less controlled the details often seem more ambiguous yet the lighting more dramatic which goes well with rugged features of a male portrait.