Monteverde Sapphire is a vibrant blue. It shades beautifully and has a wet flow. I didn’t see any feathering on Kokuyo Campus paper. There is a tiny bit of bleedthrough at the ends of strokes where the ink had pooled.
This is written with a TWSBI ECO-T medium nib.
Disclaimer: This ink was purchased by me and all opinions/photos are my own. This post was not sponsored.