To edit a linetype:
Access the linetypes library. How to
Select the linetype in the list.
In the Definition edit box, edit the linetype’s definition. Lines are defined by a series of distances separated by commas. Each number represents the length of either a line segment or space. Positive numbers create a line segment of the specified length. Negative numbers create a space of the specified length. For example, a dashed line may have a definition like 1/4”, -1/4”.
Once you’ve edited the linetype, click OK.