--- title: "Sailor Kiwa-guro: Waterproof Pigment Black Ink" canonical: "https://stationerytimes.com/guides/sailor-kiwa-guro/" description: "Sailor Kiwa-guro explained: a water-resistant nano pigment black ink in a 50 ml bottle 70 mm tall, dry time, cleaning, pen safety, sizes and where it's made." category: "Accessories" type: "Fountain pen ink" published: 2026-10-21 updated: 2026-10-21 author: "Ellis Penhale" publisher: "Stationery Times" sources: 7 products: - name: "Sailor Kiwa-guro pigment fountain pen ink, 50 ml bottle" brand: "Sailor" brand_origin: "Japan" made_in: "Japan" material: "Ultra-fine pigment (nano) ink in a glass bottle" price_band: "$$$ ($20–75 per item, typical US retail, October 2026)" manufacturer: "The Sailor Pen Co., Ltd., Kure, Hiroshima, Japan; majority-owned by PLUS Corporation since May 2022" model: "13-2002-220 (Kiwa-guro, 50 ml bottle)" mpn: "13-2002-220" gtin: "4901680184508" url: "https://sailor.co.jp/product/13-2002/" --- # Sailor Kiwa-guro: Waterproof Pigment Black Ink > Sailor Kiwa-guro is a black pigment fountain pen ink from Sailor of Japan, sold in a 50 ml (1.7 fl oz) glass bottle 70 mm (2.8 in) tall. Sailor says its ultra-fine pigment resists water, feathering and bleed-through. It's dry to the touch in about 40 seconds but can smear until 100, and pens need regular cleaning. - URL: https://stationerytimes.com/guides/sailor-kiwa-guro/ - Category: Accessories - Author: Ellis Penhale - Published: 2026-10-21 - Updated: 2026-10-21 ![50 ml Sailor Kiwa-guro bottle with black ink beside a swab card, with a written line sharp under a water drop](https://stationerytimes.com/images/raster/sailor-kiwa-guro-16x9.png) *The 50 ml bottle to scale (1 mm = 2.8 px), from Sailor Japan's dimensions.* Original drawing (SVG): . Drawings © 2026 Stationery Times, reusable with credit under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). ## Product facts | Product | Brand | Brand origin | Made in | Material | Released | Price range (typical US retail, October 2026) | |---|---|---|---|---|---|---| | Sailor Kiwa-guro pigment fountain pen ink, 50 ml bottle | Sailor (by The Sailor Pen Co., Ltd., Kure, Hiroshima, Japan; majority-owned by PLUS Corporation since May 2022) | Japan | Japan | Ultra-fine pigment (nano) ink in a glass bottle | – | $$$: $20–75 per item | - Made in (Sailor Kiwa-guro pigment fountain pen ink, 50 ml bottle): Japan. Hiroshima Prefecture's profile of Sailor says its site in Kure, Hiroshima makes fountain pens, inks and ballpoints, and the bottle's JAN 4901680184508 carries Japan's 49 GS1 prefix (it shows where the code was registered). Sailor's product page (read in full on October 21, 2026) doesn't print a country of origin. Source: https://www.pref.hiroshima.lg.jp/site/onlyonenoonezigyou/sailor.html ## Key takeaways - Sailor's Japanese site lists the 50 ml bottle (13-2002-220) at W53 × D44 × H70 mm (2.1 × 1.7 × 2.8 in) and about 203 g. - It lists at ¥2,530 (about US$16) including tax in Japan. - Mountain of Ink rates its water resistance high: the ink did not budge. - Mountain of Ink found it dry at 40 seconds but able to smear until 100 seconds. - On October 21, 2026 it was the 46th best-selling bottled ink on Amazon US, the second pigment black after Platinum Carbon Black. ## What is Sailor Kiwa-guro? **It's a black pigment fountain pen ink from Sailor of Japan, made with what Sailor calls an ultra-fine pigment it developed itself.** Kiwa-guro (極黒) means extreme black, and US shops sell it as Kiwaguro Pigmented Black or Nano Black. Sailor's Japanese page says the ink resists clogging and writes as comfortably as a dye ink, while resisting water, feathering and bleed-through, so it suits anything from illustration to official documents. Wonder Pens notes it's one of Sailor's two original pigment inks, with the blue-black Sei-boku. Sailor has made pens in Kure, Hiroshima since 1911, as our [Sailor history](https://stationerytimes.com/stories/sailor-history/) explains. On October 21, 2026 it was the 46th best-selling bottled ink on Amazon US; the only pigment fountain pen ink above it was Platinum Carbon Black, at 5th. ## Kiwa-guro specs | Spec | Value | |---|---| | Maker | The Sailor Pen Co., Ltd., Japan | | Code | 13-2002-220, JAN 4901680184508 | | Bottle | 50 ml (1.7 fl oz), glass | | Bottle size and weight | W53 × D44 × H70 mm (2.1 × 1.7 × 2.8 in), about 203 g (Sailor Japan) | | Bottle opening | 20.6 mm (0.81 in), per Goulet | | Ink type | Ultra-fine pigment (Sailor Japan) | | Water resistance | High (Mountain of Ink) | | Dry time | Dry at 40 s; shine smears until 100 s (Mountain of Ink) | | Japan list price | ¥2,530 (about US$16) incl. tax; ¥2,300 (about US$15) before tax | | Price band | $$$ ($20–75 per bottle) | Sailor's page notes that the bottle no longer comes with an ink reservoir insert. Goulet also sells Kiwa-guro as Sailor cartridges. ![Kiwa-guro 50 ml bottle to scale, with converter fills per bottle and ink properties](https://stationerytimes.com/images/sailor-kiwa-guro-fills.svg) *How many converter fills one 50 ml bottle holds (bottle ÷ capacity), with Kiwa-guro's sourced properties.* ## How water resistant is Kiwa-guro? **Very: in Mountain of Ink's test, the writing didn't budge.** Sailor's Japanese page lists water resistance first among the pigment ink's strengths, and Goulet marks it as water resistant. That makes it a pick for envelopes, signatures and line work under watercolor. A Goulet customer who paints over it in a 180 gsm sketchbook waits a few hours first for the best result. ## How does it look and how fast does it dry? **A dense, shiny black that's dry to the touch in about 40 seconds but smearable until about 100.** Mountain of Ink calls it very shiny rather than sheening, with no shading. Wonder Pens describes it as matte head-on with a hint of shine at an angle. On copy paper Mountain of Ink saw just a little feathering and no bleeding. ## Which pens is Kiwa-guro safe for? **Pens you write with often and can flush easily, ideally a Sailor.** Sailor's Japanese page says to use it in Sailor fountain pens and that it can't guarantee pens from other makers. A [Sailor Pro Gear Slim](https://stationerytimes.com/guides/sailor-pro-gear-slim/) is the natural match. Wonder Pens says you shouldn't have clogging problems with good habits: write every other day or so, don't let the pen dry out, and flush between fills. ## How do you clean it out? **Flush with water before the ink can dry in the feed, and clean the pen between fills.** Pigment particles stay put once dry, which is what makes the ink water resistant and also what makes a neglected pen hard to clear. If a pen has sat inked for weeks, soak the nib and feed in water before flushing. Don't use it in a pen you might forget in a drawer. ## How does Kiwa-guro compare with other black inks? **It's the most water resistant of the easy-flowing blacks, at the cost of more care.** | Ink | Type | Water resistance | Bottle | |---|---|---|---| | Sailor Kiwa-guro | Ultra-fine pigment | High | 50 ml glass | | [Platinum Carbon Black](https://stationerytimes.com/guides/platinum-carbon-black-ink/) | Carbon pigment | High | 60 ml glass | | [Pilot Iroshizuku Take-sumi](https://stationerytimes.com/guides/pilot-iroshizuku-take-sumi/) | Dye | None to medium | 50 ml glass | | [Noodler's Black](https://stationerytimes.com/guides/noodlers-black-ink/) | Bulletproof dye | High | 3 oz glass | ## Where is Sailor Kiwa-guro made? **In Japan.** Hiroshima Prefecture's profile of Sailor says the company's site in Kure, Hiroshima makes its fountain pens and inks, and the bottle's JAN code is Japanese. Sailor's product page doesn't print a country. Sailor has been majority-owned by PLUS Corporation since May 2022. We didn't find a Sailor date for Kiwa-guro's launch. ## Frequently asked questions ### What does Kiwa-guro mean? Extreme black (極黒). Sailor's Japanese site names the ink 極黒（きわぐろ）, and US retailers sell it as Kiwaguro Pigmented Black or Nano Black. ### Is Sailor Kiwa-guro waterproof? It's highly water resistant. Sailor says the pigment ink is strong against water, Goulet lists it as water resistant, and in Mountain of Ink's test the writing didn't budge. ### Can I use Kiwa-guro in a non-Sailor pen? Many people do, but Sailor's Japanese page tells you to use it in Sailor fountain pens and says it can't guarantee other makers' pens. Keep it in a pen you write with often and can flush easily. ### Will pigment ink clog my fountain pen? Not if you use the pen regularly. Wonder Pens advises writing with it every other day or so, never letting it dry out, and flushing the pen between fills rather than topping it up. ### Why does Kiwa-guro smear after it looks dry? Its shiny finish stays soft. Mountain of Ink found it dry at 40 seconds but still smearable until 100, so give it time on coated paper or blot it. ### Is Kiwa-guro good for drawing with watercolor? Yes, it's a sketcher favorite. Goulet says artists like it for its water resistance, and one Goulet customer uses it under watercolor and gouache after letting it cure for a few hours. ### Is Sailor ink made in Japan? Yes. Hiroshima Prefecture's profile of Sailor says its Kure site makes the company's inks, and the bottle carries a Japanese JAN code. ## Sources - [セーラー万年筆: 万年筆用ボトルインク 極黒（きわぐろ）13-2002-220 (Sailor Japan: ultra-fine pigment, 50 ml, W53 × D44 × H70 mm, about 203 g, JAN, ¥2,530; read October 21, 2026)](https://sailor.co.jp/product/13-2002/) - [広島県: オンリーワン・ナンバーワン企業 セーラー万年筆 (Hiroshima Prefecture profile: Kure site makes pens and inks)](https://www.pref.hiroshima.lg.jp/site/onlyonenoonezigyou/sailor.html) - [Goulet Pens: Sailor Kiwaguro Pigmented Black 50 ml bottled ink (square glass bottle; opening 20.6 mm; pigmented; water resistant)](https://www.gouletpens.com/products/sailor-kiwaguro-pigmented-black-50ml-bottled-ink) - [Goulet Pens: Sailor Kiwaguro Pigmented Black ink cartridges](https://www.gouletpens.com/products/sailor-kiwaguro-pigmented-black-ink-cartridges) - [Mountain of Ink: Ink Review No. 446, Sailor Kiwa-guro (40 s and 100 s dry times, high water resistance, shiny finish)](https://mountainofink.com/blog/sailor-kiwa-guro) - [Wonder Pens: Ink review, Sailor Kiwa-Guro Carbon Nano Black (care and clogging advice)](https://wonderpens.ca/blogs/pens-and-things/ink-review-sailor-kiwa-guro-carbon-nano-black) - [Amazon: Best Sellers in Bottled Pen Ink (Sailor pigment Ultra Black 13-2002-220 46th on October 21, 2026)](https://www.amazon.com/Best-Sellers-Office-Products-Bottled-Pen-Ink/zgbs/office-products/490677011)