Set the Plot Scale
Layout Settings
Set the Plot Device
Lineweights can be scaled proportionately in a layout with the plot scale. Typically, lineweights specify the linewidth of plotted objects and are plotted with the linewidth size regardless of the plot scale. Most often, you use the default plot scale of 1:1 when plotting a layout. However, if you want to plot an E-size layout that is scaled to fit on an A-size sheet of paper, for example, you can specify lineweights to be scaled in proportion to the new plot scale.
To scale lineweights, set the ScaleLineweights property to TRUE. If you do not want lineweights to be scaled, set this property to FALSE.