These are very light lines used in the process of constructing a drawing. They are for the drafter's use only.

• centerlines

• short break lines

• border lines

• construction lines

These are very heavy lines used to form a boundary.

• centerlines

• short break lines

• border lines

• construction lines

Indicates the centers of holes and symmetrical objects such as doors and windows.

• centerlines

• short break lines

• border lines

• construction lines

Shows the outline of the main features of the object. They are important lines and should be easy to see.

• centerlines

• construction lines

• guidelines

• object lines

Represent an edge that is behind a visible surface in a given view.

• centerlines

• object lines

• construction lines

• hidden lines

Used to show size and location of an object or feature.

• centerlines

• dimension lines

• object lines

• border line

Show the termination point of a dimension line.

• extension lines

• object lines

• guidelines

• construction lines

Used for hand lettering. They are drawn very light and are for the drafter's use.

• dimension lines

• extension lines

• construction lines

• guidelines

Lines used to show that a feature has been sectioned. Also called crosshatch lines.

• centerlines

• guidelines

• border lines

• section lines

Heavy lines used to show where and object is to be sectioned.

• cutting-plane lines

• object lines

• hidden lines

• dimension lines