485 x 422 pixels is the size of the 'default' Messenger backgrounds (which you can find as JPG images with a DAT extension in the %AppData%\Microsoft\MSN Messenger\user id\Backgrounds folder).
Backgrounds - by lordy on 06-27-2005 at 05:53 AM RE: Backgrounds - by Tochjo on 06-27-2005 at 11:35 AM RE: Backgrounds - by RaceProUK on 06-27-2005 at 12:37 PM RE: Backgrounds - by Tochjo on 06-27-2005 at 12:44 PM RE: Backgrounds - by RaceProUK on 06-27-2005 at 02:37 PM RE: Backgrounds - by CookieRevised on 06-27-2005 at 04:15 PM