[Tom Edgerton]

Jeff--

"High key" means all values are compressed toward the lighter range of the value scale, that is, it's a "light" drawing tonally.

"Low key" would mean that it's a "dark" drawing, that is, that all tones are compressed toward the darker end of the value scale.

Usually, this would mean that the contrast within each would be less than in a full-range drawing, as the work extends over fewer values in the scale.

A full-range drawing in terms of values would be stretched mostly over the whole value scale and might possibly include a full complement of values from 1-9. Very dark darks and very light lights. Lots of contrast, in other words.