If it is for a show or you think you may enter it into a show then you need to follow national guidelines. AQS has a description of what they want and most states I have been to follow those. A completed 4" sleeve across the back of the quilt. If you've done such a good enough job you want to display the quilt, then make the sleeve as if you were entering a quilt show.
Sorry I don't have the site right now.
ali