This kind of stroke could be attributed both to the pencil and engraving.
Looking at the works by the great masters of Renaissance you can’t help thinking it took great deal of time and intuition to create them.
There are many academical techniques and methods of hatching helping to analyze the body position and depict it on canvas.
For instance, Willian Hogarth (1697-1764) developed a system of visual mnemonics. During his walks around London, he made strokes and drew symbols on the nails of his left hand that enabled him to recall people and scenes which had made an impression on him.
The entire image of “The Holy Face” by Claude Mellan is made from one continuous spiraling line. All details of the face, as well as light and shade, are created by thickening or bends of the line.
Great art is made regardless of the technique.