Description 1 Review Sailor Sei-boku Pigmented Blue-Black fountain pen ink is a deep, rich shade of blue-black that is pigmented, water-resistant and fast drying. The 50ml cube shaped glass bottle has a sturdy design. This pigmented ink was designed for brush pens, but is safe for use in fountain pens as well. A little extra care is called for, so don't leave it in your pen for weeks on end without cleaning. The pigment particles, if left to dry, can require a little more maintenance to clean out. Sailor Sei-boku Pigmented Blue-Black fountain pen ink dries on the surface of the paper and is perfect for mixed-media or watercolor artists who use thicker sketch or watercolor paper, but this also works well for artists or others who use fountain pens, with a color wash over top. Sailor fountain pen ink is made in Japan, and is very well behaved, has good flow, and is easy to rinse out of your fountain pen. We offer Free Shipping on all orders over $69 for US customers! 1 Review Hide Reviews Show Reviews 5 Great, waterproof ink! Posted by Wayne Bosma on Apr 24th 2026 I've used this in my Sheaffer 100 (F) -- about 3 converters full so far. Depending on the paper, this might be more of a blue than a blue-black, but it's a nice color either way. It's also very waterproof (let it dry first, of course!). I soaked a piece of paper for about 10 minutes, and it looked the same coming out as going in. I haven't encountered any real problems with feathering or bleed-through, even with relatively cheap paper.
5 Great, waterproof ink! Posted by Wayne Bosma on Apr 24th 2026 I've used this in my Sheaffer 100 (F) -- about 3 converters full so far. Depending on the paper, this might be more of a blue than a blue-black, but it's a nice color either way. It's also very waterproof (let it dry first, of course!). I soaked a piece of paper for about 10 minutes, and it looked the same coming out as going in. I haven't encountered any real problems with feathering or bleed-through, even with relatively cheap paper.
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