no problem dude its easy: First if you got all finish sig, you must select all sig (press Ctrl+A on keybord) then go Edit>>Stroke then Width 1 px, Color black, Location- inside, This is the easeiest way of makeing borde.
Just grab the pencil and draw a 1px line all around the outside! Or, if you prefer, Select All and then add a Stroke [EDIT] Whoops, I replied to the last post on the first page...
I'll help you go to edit-stroke 1 px color white or fffff in the bar location inside click ok. this is for a 1 px border.