Monkey Hanger is flat looking blue ink that’s bulletproof. You can soak it in water for days and the color won’t change. That;s cool. What’s rather uncool is terrible feathering on many papers. For me it’s a deal breaker. The ink is exclusive for purepens in UK and the story behind the name is interesting.
Drops of ink on kitchen towel
Tomoe River, Kaweco Classic Sport, broad nib
Leuchtturm1917, Kaweco Classic Sport, broad nib