Inktend / Ink library / Otto F. K. Koch - Elbwasserblau
Otto F. K. Koch - Elbwasserblau
A UK ink maker (est. 1864) known for an enormous range (150+ shades) at accessible prices, including several shading and sheening standouts.
Paper & pairing
Blues and navies are the most broadly "safe" fountain pen colors: legible, professional, and unlikely to raise eyebrows in an office. This ink will behave predictably on most fountain-pen-friendly paper. Cheap, highly absorbent paper (standard copier paper) will dull any ink's saturation and can cause feathering or bleed-through with wetter nibs.
About Diamine
Founded in Liverpool in 1864, Diamine is one of the UK's oldest ink makers, known today for an unusually large range (150+ colors) at accessible prices.
Storing and using the bottle
Bottled fountain pen ink has an effectively long shelf life when kept capped and out of direct sunlight: most inks remain usable for years. The main risk isn't the ink spoiling, it's a pen sitting inked and unused for weeks: that's what causes clogs, not the ink's age.
Frequently asked questions
Similar shades By colour distance
Color shown is a close digital approximation of a typical swatch, not a calibrated color match.