ACP > Look / Feel > Skin Manager > (edit each skin as needed) > Edit CSS Advanced >

Scroll down a bit to this section...

Code: 
#ipbwrapper{ 
    margin: 20px auto 20px auto; /* centers the box, no matter the overall width, also applies a 20px gap at the top and bottom of the board */
    text-align: left; /* re_aligns text to left second part of two part MSIE centering workaround */
    /* EDIT THIS TO CHANGE THE WIDTH OF THE BOARD -> 960px is a common fixed resolution size */
    width: 98%;
}
Change the
Code: 
width:98%;
to something smaller. Try 80% as a start and adjust from there.
Lease Reviewed by Lease on . [TUT]Resizing width of skins ACP > Look / Feel > Skin Manager > (edit each skin as needed) > Edit CSS Advanced > Scroll down a bit to this section... #ipbwrapper{ margin: 20px auto 20px auto; /* centers the box, no matter the overall width, also applies a 20px gap at the top and bottom of the board */ text-align: left; /* re_aligns text to left second part of two part MSIE centering workaround */ /* EDIT THIS TO CHANGE THE WIDTH OF THE BOARD -> 960px is a common fixed resolution size */ width: Rating: 5