How to Edit Mline Styles and Draw Parallel Multi-Polylines with Ease!

Mlines in AutoCAD are quite a forgotten thing. In my practice, I see those objects rare, and when I do it tends to be very limited use. That is strange though because with Mline we can draw Multiple Parallel Polylines at once. We can also predetermine the number of parallel lines drawn. Together with their color, linetype, offset, and justification.

In my mind, the limited use of these objects is due to the troublesome editing, as you can’t use the well-known practice of Edit Vertexes of Polylines! Editing the number and style of the parallel lines is quite troublesome too! So today we will go through all these problems and drawing of Parallel Multi Lines as efficient as possible!

Create Mline Style in AutoCAD

Our first Stop will be Creating personalized Styles for Mlines we will be using. To create a Mline Style follow the steps below:

  1. To open Multiline Style Editor, type on the command line MLSTYLE.
  2. A Window will pop up where you can see the current Mline styles present in the current drawing. There hit on New… to create your own style.
    Create mline style autocad
  3. At the next stop, you have to type in the Name of the style for your parallel lines. And the starting style to use.
  4. Next is the actual Mline Style Creation as you can see on the image.
  1. Type in Description for the style if you like.
  2. Under Elements tab, you can take a look at the number, offset, color and linetype of the Parallel lines that will be created.
  3. Add or Delete new lines to the Mline style.
  4. Control the Offset of the different Lines, they don’t have to be symmetrical.
  5. Change the Color of the Parallel lines
  6. Changes the Linetype of the selected Parallel line.
  7. Controls wheather or not to have Line, Inner Arc or Outter Arc at the Start/End of the Multi line object.
  8. Lets us Fill the space between those parallel lines.
  9. Controls weather or not to add perpendecular line at the Mline Vertexes.
  10. Lets us preview the changes live while we are making them.
    Note that the preview is on separate window and could be hidden from view.

Hit OK and Set the new style to be Current.

To draw in multiple parallel lines using Mline and our new Mlstyle just type in Ml and start drawing!
how to draw mline autocad

Edit Mline Object

Our second stop will be Editing Mline Objects. As I previously said, this is maybe the biggest reason, why people don’t like and won’t use Mlines.

To edit the geometry of an existing Mline we can use the grips in order to move vertexes around, but when it comes to adding and erasing new vertexes we need to use MLEDIT command. It actually can do many more things as you can see in the picture below.

We won’t stop on each and every one of those as they are pretty easy and straightforward.

The problems start when we want to add an additional parallel line to the already existing Mline or when we try to add Line Width to the Mline object.

That is because we can’t change the style of an existing Mline object, nor we can change the Line width of the Mline Parallel lines.
We can’t even Explode the Mline because it leaves us with many Lines that need to be joined in order to get polylines that can be edited accordingly. This is all too time-consuming and inefficient. So how to draw Multiple Parallel Polylines then?

Draw Parallel Multi-Polylines (a very Improved Mline)

To Quickly draw Multiple Parallel Polylines we are going to use a LISP created by Lee Mac. He is one of the most knowledgeable AutoLISP people I’ve ever seen and has helped thousands of people with his great programs.

The one we are looking at today is his Multi-Polyline which enables us to create Multiple Parallel Polylines with the appearance and the Style of Mline Object. This will enable us to change the Mline width as the resulting objects are separate Polylines. The Lisp uses the existing Mline styles that you have in the drawing to draw the Polyline objects.
To draw the Improved Mline follow the steps below:

  1. First, download the Lisp from Here. And Load it into AutoCAD (How to load Lisp in AutoCAD).
  2. Then, start the routine by typing MPL on the command line.
  3. AutoCAD will prompt to Specify start point or [Justification/Scale/STyle]: Now, you can directly start drawing the Multiple Parallel Polylines or use the other options:
    • Justification – lets you choose how the Polylines are drawn between the vertexes that you specify.
    • Scale – Controls the offset between the Parallel polylines. Default value is determined by the Mline Style (check first paragraph).
    • Style – Lets you choose the Mlstyle for the Polylines.
  4. Draw the Multi-Polyline the same way as drawing a Mline object.
how to draw multiple parallel polylines in autocad

That’s it, now, instead of one, hard to edit Mline object we have multiple parallel Polylines that can be easily edited together. We can now easily choose the desired polyline and change it’s width, that way we will get a Mline with different line widths.

I hope you find this post informative. You can check our other AutoCAD-related posts to learn more useful tricks!

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