Best Blue Fountain Pen Inks: 10 Bottles I Have Used and Ranked

Blue is the most crowded shelf in fountain pen ink, and most of the differences that matter are invisible in a swatch. A colour that looks gorgeous painted on Rhodia can feather into a smudge on a photocopier’s paper, take ninety seconds to dry under a left hand, or wash off completely the first time a raindrop finds your notebook.

These ten are bottles I have actually emptied, or come close to. They are ranked on how they behave in use, not on how they photograph.

Prices move constantly on all of these. The figures below are what I paid or what I last saw them at — treat them as a band, not a promise.

How I Tested These

Every ink below went into the same two pens — a Lamy Safari with an EF nib and a TWSBI Eco with a medium — so nib width is not doing the work. Each was written on three papers: 80gsm office copy paper, a Leuchtturm1917 (80gsm, notoriously ink-sensitive), and Rhodia 80gsm.

For each I logged four things: dry time under a finger drag at ten-second intervals, feathering on the copy paper, show-through on the Leuchtturm, and what happened after thirty seconds under a running tap. Those four numbers decide almost everything about whether you enjoy an ink day to day.

The Ranking

1. Pilot Iroshizuku Kon-peki — Best Overall Blue

Shade: Bright azure | Dry time: ~15s (EF) | Water resistance: Poor | Bottle: 50ml

Kon-peki is the ink I recommend without qualification. It is a vivid, slightly turquoise blue with genuine shading — light strokes go pale, heavy ones pool dark — and it is remarkably well-behaved for something this saturated. On copy paper it holds its line where inks half as bright feather badly.

The catch is water. A splash lifts it almost entirely. Do not address an envelope with it in the rain and do not use it for anything you need to keep. Within those limits it is the most enjoyable blue I own.

2. Waterman Serenity Blue — Best Everyday Workhorse

Shade: Classic mid-blue | Dry time: ~10s | Water resistance: Poor | Bottle: 50ml

Formerly Florida Blue, and still the safest ink in the hobby. Wet, lubricating, almost impossible to make feather, and it will unclog a stubborn pen just by being easy to flow. If a pen is misbehaving this is the first thing I put in it as a diagnostic.

It is not exciting. That is the point — this is the bottle you keep for filling everything when you are not in the mood to think about it.

3. Diamine Oxford Blue — Best Dark Blue

Shade: Deep navy | Dry time: ~20s | Water resistance: Moderate | Bottle: 80ml

A properly dark, slightly dusty navy that reads as almost-black at a distance and unmistakably blue up close. It is the most professional-looking ink here — the one I would use on a job application. Diamine’s 80ml bottles are also the best value in the hobby by a wide margin.

Slower to dry than the Waterman and it will show through thin paper. Worth it for the colour.

4. Pilot Iroshizuku Asa-gao — Best Blue-Purple

Shade: Morning-glory blue with violet lean | Dry time: ~15s | Water resistance: Poor

Asa-gao sits between blue and violet and shifts depending on the light, which sounds like marketing until you write a page and notice it. Beautifully behaved, same as everything in the Iroshizuku line. This is the bottle.

5. Pilot Iroshizuku Shin-kai — Best Blue-Black

Shade: Deep grey-blue | Dry time: ~18s | Water resistance: Moderate

A stormy blue-black with grey in it. It is the most “serious” ink on this list and the one that suits a broad nib best, because the shading only really appears when you put enough ink down. Shin-kai is here.

6. Diamine Royal Blue — Best Value

Shade: Bright classic blue | Dry time: ~12s | Bottle: 80ml

Eighty millilitres of a perfectly good bright blue for the price of a 50ml bottle of anything Japanese. Nothing here is remarkable and nothing is wrong. If you journal daily and go through ink quickly, start here and spend the difference on paper.

7. Lamy Blue (T52) — Best for Beginners and Cleaning

Shade: Bright, slightly washed mid-blue | Dry time: ~10s | Water resistance: Very poor

Lamy’s house blue washes out of everything — pens, fingers, shirts — which makes it the least stressful ink to hand someone learning. That same property makes it useless for anything permanent. The bottle has a built-in blotting-paper roll in the base, which is a genuinely good piece of design. The T52 bottle.

8. Pilot Iroshizuku Ama-iro — Best Light Blue

Shade: Pale sky | Dry time: ~12s

Very pale, very pretty, and genuinely hard to read in a fine nib under poor light. This is a broad-nib ink or a margin-notes ink, not a daily driver. Judged on those terms it is lovely. Ama-iro here.

9. Noodler’s Blue — Best Water Resistance

Shade: Strong mid-blue | Dry time: ~25s | Water resistance: Excellent | Bottle: 3oz

The only ink on this list that genuinely survives water — the tap test barely touched it. That resistance is the whole reason to own it, and it costs you dry time and a slight tendency to feather on cheap paper. Noodler’s also runs wet enough to be a poor choice for a pen that already flows generously. Buy it for records, not for journaling.

10. Waterman Mysterious Blue — The One I Use Least

Shade: Muted blue-grey | Dry time: ~12s

Perfectly competent and slightly joyless — a grey-leaning blue that never quite decides what it is. It behaves as well as everything Waterman makes, which is why it is on the list rather than off it. If you want a subdued blue that will not misbehave anywhere, it does the job.

If You Only Buy One

Kon-peki, unless you write left-handed or need the writing to survive water. In that case take the Noodler’s and accept the longer dry time, or the Diamine Oxford Blue as a middle path.

If you would rather test before committing to bottles, I have written about using sample services — it is how I got through most of these without a shelf of half-empty glass. And if permanence is your actual requirement, the waterproof inks guide is the more useful page.

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