On Inks
I get lots of questions about inks. There are a lot of good ones out there and a growing number of bad ones.
Be sure any ink you use is made for fountain pens, not dip pens or drawing pens. Never use India ink.
A good rule of thumb is to use an ink made or sold by a fountain pen manufacturer. They are generally not going to make an ink that messes up pens and causes them to have to do warranty work.
The sole exception would be Diamine inks, not made by a pen maker, but very safe and offered in a wide variety of colors and tints. However, be aware that Diamine is now making a number of shimmer and glitter inks, so be careful in your choice.
My preferred ink list includes, in no great order of preference, Parker Quink, Pelikan 4001 or Edelstein, Waterman’s, Aurora, Pilot, Diamine.
There is one important exception to this, however, and that is that several noted ink makers, including Diamine and Pelikan, are now marketing shimmer inks. I continue my warranty exclusions for the use of these inks.
Please note: the use of pigmented, shimmer, or glitter inks will void The PENguin warranty. I cannot be responsible for pens in which those inks have been used.
Finally, some disclosures. I am not a chemist and don't play one. I have never used pigmented inks but have gathered my data directly from users and pen manufacturers.
Most importantly, I have repaired pens that have used these inks and have seen the staining and the actual corrosion of parts.
So, for all those reasons, I strongly recommend against the use of these inks and will not warranty pens in which they are used.