AutoCAD’s Multiline command creates line objects that consist of as many as 16 parallel elements. For example, you could create a “pipe” multiline that creates the walls and inner diameter. The first step is to create a multiline style by typing Mlstyle at the command prompt or selecting it from the Format menu.
Caption: AutoCAD’s Multiline Style editor.
AutoCAD provides the Standard style as the default. To create a new multiline style, select New and enter a name.
Caption: Name your multiline style and select an existing style as a starting point.
Then select a style in the Start With window—that will be the style on which the new one is based. Select Continue to assemble the parts of your multiline style. Add elements and set their color and linetype (bylayer and byblock are options). The Offset value is distance from the multiline’s origin (or centerline). You can enter negative values. Next, set multiline properties such as fill color and start and end terminations. Options for terminations include a line drawn between the two outermost elements (you can set an angle for the line), an outer arc drawn tangent to the ends of the two outermost elements, and inner arcs drawn tangent to the ends of each pair of elements. You can specify angles for all of the ending options.
Caption: Assemble your multiline style by adding elements and caps.
Once you finish building your multiline, you can save it to an external file so it can be loaded in other drawings. You can either save to the default acad.mln file or create a new one.
To put your multiline into action, type in Mline at the command prompt or select it from the Draw menu. Before drawing, you can set justification and scale.
Justification options are Top (the default), Bottom, and Zero (origin). This determines where the line is drawn in relation to the cursor.
Multiline scale controls the overall width of the multiline using the current units. Multiline scale does not affect linetype scale. If you change the multiline scale, you might need to make equivalent changes to the linetype scale to keep dots and dashes in proportion.
Style lets you type in the name of an Mline style.
You then draw your multiline just as you would a regular line, by specifying points. Undo erases the last segment drawn, and Close connects the last segment drawn back to the starting point.
Caption: Closed multiline is all one object.