Quick Reference Guide for Noodler's Ink
 

Given the near-total lack of activity in this newsgroup, only you and I
seem to have seen this attack on Nathan's products. That said, I no
longer use Private Reserve or Noodler's Ink because of clogging problems
in my pens, including a couple that are just no longer usable (and I
don't remember which ink caused the problem, so I don't want to
specifically blame either but it was one of the two). I have enough old
"real" fountain pen ink (Sheaffer, Parker and Waterman) to hold me for
the rest of my days, so I use that and have dumped all the Noodler's and
PR inks.

That said, all of my direct experiences with Nathan were standup and
excellent. He is a scupulous guy in my experience, and he did some
fantastic pen restoration work for me- pens that are in regular use
10-15 years later and will probably outlive me.