Check out the Federal Reserve seal on this $5 bill. It appears to be over inked. Is this an error worth saving? Compared to a normal $5 bill:
This happens quite often when the wiper blades that scrape off excess ink from the printing cylinder become dull allowing over inking. I don't think it will add any extra value. On the other hand ink smears do command a premium but only depending upon finding a buyer who collects them.