guess the ink!

[PithyProlix]

Robert Oster Chicago
Noodler's Akhmatova

[mizgeorge]

Kiwi Rainbow in a Bottle
Vinta Sodalite
or if the 'nostalgic' is a clue, perhaps Noodler's Pushkin

[Yazeh]

Ink is not green.
It is not waterproof.

[mizgeorge]

It's very green on my screen - I might be overdue for a monitor calibration!

Waterman mysterious blue
Quink blue black

[Yazeh]

See if this photo is better:

20230106_094751.jpg

[mizgeorge]

Diamine Prussian Blue
Skrip washable blue
Akkerman Laan Van Nieuw Oost Indigo
I would have said Salix, but you said it's not waterproof

[Yazeh]

Nope. None of the above.

[DrPenfection]

Van Dieman's European Honey Bee Eater Breast / Wing

[DrPenfection]

FWP Tokyo Bay Blue

[DrPenfection]

Birmingham Sterling Silver / Kingfisher / Shortleaf Pine / Sea Holly / Eroded Bronze / Damselfly

[Yazeh]

Not yet !

I would say, Dr.P and mizgeorge have a particular relationship with this ink

[DrPenfection]

Kobe #68 - West Pearl Blue
Colorverse a And / aCMA
Montblanc Glacier (but this really doesn't look like it much)
Taccia Grey Jeans / Washed Jeans
Troublemaker Abalone

truthfully, I am not sure if this is grey, blue, green or all of the above

[Yazeh]

It's a light blue ink.... but none of the above.
It's not Japanese nor Korean...

[DrPenfection]

well then how about Noodler's Blue Nose Bear / dostoevsky / tolstoy / lermontov

[DrPenfection]

or maybe Noodler's Lightning Blue / eel turquoise / blue ghost

[Yazeh]

and not Noodler's....

[DrPenfection]

Vinta Kislap / Blue Perya Floss / Deep Water Lucia
Akkerman 08 / 09
Pennonia Danube

[DrPenfection]

Van Diemans Pixies Parasols
Callifolio Oliphants / Ohlanga / Bonne Esperance / Oconto / Equinox 6
FWP Blue Cotton Candy / Storied Blue

[DrPenfection]

Robert Oster Chicago
Wearinguil Lost
GVFC Gulf Blue

[Yazeh]

FWP Storied Blue

Yay, indeed it's FWP Storied blue. A brand you don't like and mizgeorge. I believe, loves
I fear there will be a bit head banging again , oh dear!