Alphabet of Lines and Symbol Construction Drawings

Line Weight

The thickness or colorfulness of a line on a construction drawing, where a thicker line has a higher weight to help distinguish shapes from surface details.

Heavy Solid Line

A continuous line with a heavy weight used on construction drawings to describe objects and represent visible edges.

Light Solid Line

A solid line used on drawings for dimensions, leaders, and items that do not represent an actual physical object.

Hidden Lines

Dashed lines used to represent important objects that are concealed from view, such as concrete footings beneath the ground surface.

Phantom Lines

Dashed lines used to show important objects located above the cutting plane (such as roof edges or ceiling beams) or to show alternative positions and movement ranges of objects (such as opening doors).

Center Lines

Lines drawn with a dot-dash pattern to show that an object is symmetrical and to mark the center point of items like columns, doors, or windows.

Break Lines