With the Draw Line Weights command, line thicknesses defined for primitive objects are displayed on the plan view. The line thickness display is turned off by clicking the command again. Defined line thicknesses are only displayed on the screen. It does not affect the drawing outputs. Line thicknesses are defined in the object settings dialog.
Location of Draw Line Weights Command
You can access it under the ribbon menu View tab View title.
You can also access the draw line weights command from the quick entry toolbar.
Click the draw line weights icon.
Line thickness defined.
Layout plan when draw line weights is not active
Layout plan with draw line thickness active