Which line type is commonly used to indicate the outline of an object?

The line type that is commonly used to indicate the outline of an object is object lines. Object lines are drawn as solid lines and represent the visible edges or contours of an object in technical drawings. They provide a clear distinction of the object's shape and are fundamental in communicating the details of the design effectively.

In drafting and technical drawings, proper use of line types is crucial for clarity. Object lines are typically the most prominent lines on a drawing, making it easy for viewers to immediately identify the primary element of the design. This distinction is important in both engineering and architectural plans, where understanding the physical elements being represented is essential for accurate interpretation and construction.