drawings in which forms are indicated primarily by lines, with few or no areas of continuous tone

drawings produced with the aid of instruments such as compasses or T-squares

Architectural drawings or drawings of other subjects, characterized by the depiction of shadows, textures, sometimes colors, often executed with watercolor washes, and showing some setting. Intended as visualizations of the full conception of a project or as an accurate record of the work depicted.

generally any drawing made without the use of devices such as t-squares, triangles, or other mechanical means of rendering or tracing

particular arrangements of vertical elements of a building, either exterior or interior. For the external areas of buildings, not necessarily restricted to surface features, use "fronts (architectural)." For the features of a primary front, restricted for the most part to surface elements in a single plane, use "façades"

refers to drawings or works in any other two-dimensional medium that employ perspective, meaning that they are executed by a systematic technique that creates the illusion of recession from a two-dimensional surface