I loaded up my Airmail 444 eyedropper fountain pen sporting a FPR flex nib with Chesterfield Archival Vault ink. Reportedly, it is custom branded Diamine Registrar's ink sold exclusively by www.xfountainpens.com.
As it is an iron gall formulation designed for fountain pens, it can be used safely in many pens with a bit of extra care.
I think that the Airmail 444 is a good choice for this type of ink for the following reasons:
- It is an eyedropper and there are no metal parts that can corrode other than the nib.
- The nib can be replaced easily and inexpensively even if corrosion occurs.
- It uses a very simple ebonite feed that can be cleaned easily.
- The pen can be disassembled completely for thorough cleaning.
- The 444 has ample ink holding capacity so that the pen will not dry out quickly.
Cleaning the pen requires a bit of extra effort since the ink stains the clear barrel quite a bit. I just used mildly soapy water, some cotton swabs, tissues and a bit of elbow grease .
I purchased my Airmail pen and FPR flex nib from www.fountainpenrevolution.com in India. I think it is a great combination!
For more information on the pen and the ink:
For more information on iron gall ink: