Which drafting tool is most commonly used to create straight lines?

The tool that is most commonly used to create straight lines is the T-square. It features a long horizontal bar, which is typically used in conjunction with a drafting table. The T-square allows the user to draw perfectly straight horizontal lines across the paper, while its vertical edge can be used to draw vertical lines when paired with a parallel ruler or other drafting tools. The design of the T-square, with its T shape, enables it to anchor securely to the edge of the drafting table, providing stability when drawing.

Other tools have specific functions that do not prioritize the creation of straight lines alone. For instance, a compass is primarily designed for drawing arcs and circles, while a protractor is used for measuring angles. A scale ruler provides various measurements but does not inherently create straight lines on its own. Each of these tools plays an important role in drafting, but the T-square is uniquely positioned as the go-to tool for the creation of straight lines.