Just a quick little test and so far, so good. Very bright and seems to be "true" red. Not too dark or too pink when dried. Neither are bad just not what I'm after sometimes.
There seems to be a bit of gold sheen, too, which I didn't expect (but should have, seems like almost all reds have gold sheen)
Writing sample below is on Iroful (top, first) and Midori MD (bottom, second)
Water resistance seems great so far, I've had a water drop sitting on a letter until it evaporated with no change. Rubbed a few letters with a wet finger and nothing moved. Had to really exert a bunch of pressure to even get a tiny faint smear but it didn't affect readability.
Writes a bit on the wet side, especially compared to typical Diamine inks. Could be the pen, though.
Bonus microscope video of it drying and the sheen becoming visible.
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