Fading signatures on balls
 

I have a few signed balls in my collection that are fading. They're not in direct sunlight, never have been, but it's just happened over the years.

Is there ANYTHING I can buy that will protect against further degradation? Any recommendations on cases that will protect the signatures from further fading? I've had them in basic plastic ball cubes.

Specifics on what I'm dealing with are HOF signed balls, obtained at card shows when I was a kid, on low grade non-MLB balls, in ballpoint ink.

I always buy the more expensive Ultra Pro ball holders. Also it maybe the ball itself meaning the quality of the leather or is it a pleather ball and finally how many times it was handled before and after signing since sweat etc.. from the hands can affect signature quality. Finally the quality of the pen/ink can also affect the signature.

I've never found a way to stop it once it sets in. It's something in the leather. It just doesn't hold the ink after a while.