A Treatise on Painting/Chapter 40
Chap. XL.—Of the Naked.
When a figure is to appear nimble and delicate, its muscles must never be too much marked, nor are any of them to be much swelled. Because such figures are expressive of activity and swiftness, and are never loaded with much flesh upon the bones. They are made light by the want of flesh, and where there is but little flesh there cannot be any thickness of muscles.