This video demonstrates about how the global line style scale factor will apply on Custom Linestyles.
"The Global Linestyle Scale Factor will only apply to custom linestyles. It will not effect standard linestyles 1 - 7. It is because the two different linestyle types are created differently. Custom linestyles have the dashes and spaces defined in drawing units and the scale factor can be applied to them. They also maintain their actual lengths and will appear longer or shorter depending on how far you are zoomed in or out. The standard linestyles are defined in screen pixels. They will always appear the same display length, on the screen, no matter how far you zoom in or out".
Click the video below to play it. To view in fullscreen mode, first click the YouTube link at the bottom of the video to launch the video on the YouTube site. Then, click the fullscreen button (rightmost button at bottom of video).