Change GNOME border width
To change border widths, simply open up the theme's Metacity XML file. For example, Human's theme is located in /usr/share/themes/$THEME_NAME/metacity-1/metacity-theme-1.xml Then, change the values in the following lines: <distance name="left_width" value="3"></distance> <distance name="right_width" value="3"></distance> <distance name="bottom_height" value="4"></distance>