>>7781186
Up until (and including much of) the 19th century, most painters made very precise drawings as the basis for their paintings. They would start with rough compositional sketches. Once the composition was settled upon, every major figure in a painting was isolated and studied separately, as with important/challenging heads, hands, feet, etc. Every detail was worked out before bringing it all together in a "cartoon," or full-scale preparatory drawing, which was then carefully transferred to the surface which was to be painted.
Later, many painters took a more direct approach, making only a rough charcoal under-drawing or going straight to paint. This change coincided with a greater emphasis on the effects of light and color and lesser emphasis on form and linear design.
Ingres is an example of the former, Sargent the latter.