| A | B |
|---|
| Construction | lightly drawn line to guide other lines and shapes |
| Object | darkly drawn line that defines an object |
| Hidden | dashed line that shows an outwardly invisible detail |
| Center | line that defines the middle of arcs |
| Section | line that shows cut away detail |
| Dimension | line with arrows on both ends that shows a distance |
| Extension | line that shows where a dimension begins and ends |
| Leader | line that shows dimension of arcs |
| Precedence | rules that govern which lines |
| Longbreak | line that shows foreshorten uniform objects |
