Selected Bibliography Architectural Graphics | Page 146

TONAL VALUES IN ARCHITECTURAL DRAWINGS In paraline drawings, the t hree-dimensional nature of forms and the spaces they define aremorereadily apparent than in plan, section, and elevation drawings. Tonal values are t hereforeused primarily to articulatethe orthogonal relationship between horizontal and vertical planes. • It is usually better to apply tonal values to the horizontal rather than the vertical planes of a para line drawing. Toning the horizontal planes not only establishes avisual base for the drawing but also aids in defining the shape and orientation of the vertical planes. • Indicate cuts to reveal the interior spaces of abuilding with either acontrasting line weight or achange in tonal value. 140 I ARCHITECTURAL GRAPHICS