What type of line in the alphabet of lines is used to indicate the shape of an object on a blueprint?

The type of line used to indicate the shape of an object on a blueprint is the object line. Object lines are solid and bold, clearly defining the outlines and boundaries of an object being represented in the drawing. This is essential for anyone interpreting the blueprint as it communicates the fundamental geometrical and physical characteristics of the item. By using object lines, draftsmen can effectively convey the dimensions and shape, making it easier for builders, architects, and engineers to understand the design intent. The clarity provided by object lines is critical in ensuring that the intended design is accurately constructed.