Feeds and nibs: I owe one older and two newer Indigraph pens. The older, first line model is compatible to Schmidt FH241 nib and feed units (=triple). I use a very fine xxxf flex nib in it. The two newer models - mine are from last and this year- are without any problem fully compatible to JoWo#5 triples - for example to find in cheaper Faber Castell fountain pens as Basic, Ambition or Essentio. Can be bought single, too. There are even nice special nibs (Fude, Architect) from Indigraph itself. In new versions the problem with the narrow cap band is nicely solved and some more colourful rings available. I like my Indigraph pens, because the reservoir is additionally very useful to keep high pigmented, colourful fountain pen inks fresh and they don´t become darker and stronger satured after a week or two in a usual FP. Together with the easy nib changing makes it a sturdy EDC pen for both writing and drawing with different media. No, I´m not paid for this comment but convinced of this unusual pen and the made improvements. Few alternatives or similarities.
Feeds and nibs: I owe one older and two newer Indigraph pens. The older, first line model is compatible to Schmidt FH241 nib and feed units (=triple). I use a very fine xxxf flex nib in it. The two newer models - mine are from last and this year- are without any problem fully compatible to JoWo#5 triples - for example to find in cheaper Faber Castell fountain pens as Basic, Ambition or Essentio. Can be bought single, too. There are even nice special nibs (Fude, Architect) from Indigraph itself. In new versions the problem with the narrow cap band is nicely solved and some more colourful rings available. I like my Indigraph pens, because the reservoir is additionally very useful to keep high pigmented, colourful fountain pen inks fresh and they don´t become darker and stronger satured after a week or two in a usual FP. Together with the easy nib changing makes it a sturdy EDC pen for both writing and drawing with different media. No, I´m not paid for this comment but convinced of this unusual pen and the made improvements. Few alternatives or similarities.