Understanding Line Weight Scaling

Reference Number: KB-00705
Last Modified: December 9, 2016

The information in this article applies to:

Chief Architect Premier or Chief Architect Interiors


I would like to understand how the Line Weight Scale and line weight scaling options work. What do these do and how can I best implement them?


The weight of a line refers to its thickness on the printed page and is described in absolute terms as a fraction of a unit, often 1/100th of a millimeter or 1/1000 of an inch.

In Chief Architect, line weights are assigned to objects, patterns, and layers using whole numbers that correspond to the numerator of this fraction. You can specify the Line Weight Scale by defining the denominator and the unit used in this fraction in the Drawing Sheet Setup dialog.  

The settings in the Drawing Sheet Setup dialog for floor plan view are independent from the settings for a CAD detail, cross section view, or Layout file, even if they are part of the same project.

While typically the default line weights set in the plan will work for most normal drawing practices, your preferred line weights and line weight scale can be saved in your template plan and layout files.

The method for specifying an object’s line weight depends on the object and the type of view.

  • Most objects’ line weights can be set by layer.

  • Some objects’ line weights can be set in their specification dialog.

  • The line weights for walls in floor plan view are defined by wall type in the Wall Type Definitions dialog.

  • The line weights of material pattern lines, which are visible in Vector Views, can be set in the Define Material dialog.

  • The line weight for fill patterns is set for individual objects in their specification dialog.

  • The line weight applied to surface edges in Vector Views is determined by the line weight setting for the object's layer or the object's settings as set in 3D> 3D View Defaults .

  • The end cap length of dashed lines in floor plan view is set in the Preferences dialog.

  • An assigned line weight of 0 draws a line weight of 1 pixel, the thinnest line weight a printer allows. How thick this is varies from printer to printer.

Line Weights and Scale

When a view is sent to layout, line weights may be affected by the drawing scale selected for the view. This occurs when the layout view’s scale is different from the drawing scale of the original view.

For example, assume that you have an object in a view with a line weight of 20, and that the view’s drawing scale is 1 mm = 50 mm.

  • If you send the view to layout at 1 mm = 25 mm scale, twice the original scale, the resulting printed line weight for this object will increase to 40 instead of 20.

  • If you send the view to layout at 1 mm = 100 mm scale, half the original scale, the resulting printed line weight for this object will decrease to 10 instead of 20.

  • You can specify the drawing scale for Cross Section or Elevation view by opening the Drawing Sheet Setup dialog while in that view.

  • For any layout view, you can specify whether the original line weight is maintained or not in the Send to Layout dialog and Change Scale dialog. 

Note: Under most circumstances, you should select 'Use Layout Line Scaling' when sending views to layout. If 'Use Layout Line Scaling' is enabled, line weights are no longer scaled and the dashed lines display at the same size as in the original view. 

Printers and Line Weights

Line weight and print scaling are subject to the limitations of the printer being used.

For example, you will not be able to see the difference between a line that is 1/150th of an inch wide and one that is 1/300th of an inch wide when they are printed using a printer that prints 150 dots per inch (DPI).

That is, a CAD line with a line weight of 1 will look the same as a CAD line with a line weight of 4 when the Line Weight Scale is set at 1 = 1/600th of an inch and you print to a printer capable of 150 DPI.

Setting an object’s, or group of objects’, line weight to zero causes the lines to print as thinly as possible.

Note: The default Line Weight Scale of 1 = 1/100 mm makes it easy to meet many professional drawing standards and in most cases should not be changed.

More information on Line Weights and Scaling can be found in the Line Weights section of the Reference Manual, located in the software's Help Menu.

You may also find it helpful to review the online tutorial training videos on this topic to gain further understanding about Line Weights.