InktendInktend / Ink library / Cobalt Blue
Cobalt Blue
A modern line of European-made bottled inks in vibrant classic and shimmer shades made to pair with the Estie pens.
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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 Esterbrook
Originally founded in Camden, New Jersey in 1858 and once the best-selling pen brand in America; the name was revived in 2018 under new ownership, best known today for the Estie.
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.