Shading

Definition and stakes

George G. André,  The Draughtsman's Handbook of Plan and Map Drawing

“ Section V.—Shading.
In mechanical and architectural drawings, shade lines must be considered rather as embellishments than constituent parts of the drawing. They are, however, frequently employed; and as their incorrect use may deceive the eye with respect to the intention of the designer, it becomes an important matter to know when to apply them with propriety.
”
Source: Gutenberg

Get perspective with Kwize: daily news enlightened by great literature