A. All engraving must be cut work;--that is its differentia. Unless your effect be produced by cutting into some solid substance, it is not engraving at all.
B. The proper methods for light-and-shade drawing vary according to subject, and the degree of completeness desired,--some of them having much in common with engraving, and others with painting.
C. The qualities of a light-and-shade drawing ought to be entirely different from those of a painting. It is not a deficient or partial representation of a colored scene or picture, but an entirely different reading of either. So that much of what is intelligible in a painting ought to be unintelligible in a light-and-shade study, and vice versā.
You have thus three arts,--engraving, light-and-shade drawing, and painting.
Now I am not going to lecture, in this course, on painting, nor on light-and-shade drawing, but on engraving only. But I must tell you something about light-and-shade drawing first;