Which term describes written notes added to drawings to explain materials, dimensions, functions and design decisions?

• A. Orthographic drawing
• B. Design specification
• C. Annotation
• D. Isometric drawing

Answer: (C)

Written notes attached to drawings that explain materials, dimensions, functions and design decisions are called annotations. Annotations sit with the drawing to convey details that aren’t captured by the lines and symbols alone, such as what material to use, finishes, tolerances, and the reasoning behind a design choice. They help everyone from designers to fabricators and inspectors understand how the part should be made and why certain decisions were made.

Orthographic drawings describe views and shapes, but the notes themselves aren’t the drawings. Isometric drawings are 3D representations of the same geometry. A design specification is a separate document outlining requirements, not the notes added directly on the drawing.