Blue is, with black, the main default colour of ink; most people will quickly free-associate “ink” and “blue”. Unlike black, there’s rather more variation available than “really quite” and “not so very”, so this is a very big category. I have seen that some etiquette manuals of bygone days equate blue ink with immaturity, since historically blue was more usually offered in a washable variation– some European manufacturers offer “ink eradicators” designed to work with specific school-house blue inks– but I would not let that drive your choice.
| Bright | Somber |
 Herbin Diamine Herbin Diamine Diamine Iroshizuku Noodler’s Skrip Herbin Edelstein Quink Waterman Herbin Diamine Kaweco Namiki Noodler’s Diamine Noodler’s Private Reserve Noodler’s Noodler’s Lamy Skrip Montblanc Waterman Quink Camel Pelikan Diamine Noodler’s Diamine Organics Studio Wancher Diamine |
Waterman Diamine Herbin Noodler’s Quink Kaweco Diamine Herbin Diamine Rohrer & Klingner Herbin Diamine Diamine Skrip Organics Studio Noodler’s |