Around the mid 2000’s, I noticed my Ampex tapes started to sound muddy and were leaving a lot of residue on the tape heads, pinch rollers, and transport mechanism so I had to stop using them (because they sounded like crap).
@oldschool1948 This is the shedding to which I was referring in my prior post.
Tapes that have this problem, if not too severe, can be baked in an oven at low temperature to chase out the moisture that is causing the shedding.
About 175 degrees works; you need at least 2 hours. Its better if you remove the tape from the reel (this have what is known as a 'pancake') so the moisture can leave easier. But I've baked tapes without doing that and its worked fine. We keep a toaster oven in the studio for this purpose.