"He who marches out of step hears another drum." ~ Ken Kesey
Since you mentioned this, then I'm think thinking that you've ran across situations were the backs have had flaws? Is this semi common?
That's not a tip or a trick Frog. Shoulda' posted that under "this is how you do it right".
Says the guy who only recently started pushing his squeegee!
Every arrow I have ever found has never been pointing at a defect. Just randomly pointing.