---
title: "Platinum SPN-100A Ink Cartridges: 1.2 ml, 9 Colors"
canonical: "https://stationerytimes.com/guides/platinum-spn-100a-ink-cartridges/"
description: "Platinum SPN-100A fountain pen cartridges: two 1.2 ml cartridges a pack, nine dye-ink colors, which are acidic or neutral, Japanese price, pen fit, US stock."
category: "Accessories"
type: "Ink cartridges"
published: 2026-11-02
updated: 2026-11-02
author: "Ellis Penhale"
publisher: "Stationery Times"
sources: 2
products:
  - name: "Platinum SPN-100A fountain pen ink cartridges, pack of 2"
    brand: "Platinum"
    brand_origin: "Japan"
    made_in: "Not stated"
    material: "Water-based dye ink (Platinum Japan)"
    price_band: "$ (under $5 per item, typical US retail, October 2026)"
    manufacturer: "Platinum Pen Co., Ltd. (Japan)"
    model: "SPN-100A"
    url: "https://www.platinum-pen.co.jp/products/ink/2872/"
---

# Platinum SPN-100A Ink Cartridges: 1.2 ml, 9 Colors

> The Platinum SPN-100A is Platinum's standard water-based dye ink cartridge for its fountain pens. Platinum Japan lists a pack of two 1.2 ml cartridges at ¥165 (about US$1.00) with tax, in nine colors from black to brown. It labels the blue-black acidic, the light blue neutral and the other seven alkaline.

- URL: https://stationerytimes.com/guides/platinum-spn-100a-ink-cartridges/
- Category: Accessories
- Author: Ellis Penhale
- Published: 2026-11-02
- Updated: 2026-11-02

![Nine Platinum SPN-100A two-cartridge packs drawn to scale at 38 by 115 mm, one for each of the nine ink colors](https://stationerytimes.com/images/raster/platinum-spn-100a-ink-cartridges-illustration-16x9.png?v=52ae97c6)

*Nine packs at Platinum Japan's 38 × 115 mm (1 mm = 2.4 px); the cartridge shapes and tints are representative.* Original illustration made for this guide. © Stationery Times. Original drawing (SVG): <https://stationerytimes.com/images/platinum-spn-100a-ink-cartridges-illustration.svg?v=ef29f353>. 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) |
|---|---|---|---|---|---|---|
| Platinum SPN-100A fountain pen ink cartridges, pack of 2 | Platinum (by Platinum Pen Co., Ltd. (Japan)) | Japan | Not stated | Water-based dye ink (Platinum Japan) | – | $: under $5 per item |

- Made in (Platinum SPN-100A fountain pen ink cartridges, pack of 2): Not stated. Platinum Japan's product page gives capacity, size, weight, price and color codes but no country of manufacture, and Yoseka's page doesn't state one either. Source: https://www.platinum-pen.co.jp/products/ink/2872/

### Platinum SPN-100A fountain pen ink cartridges, pack of 2 colors

- Ink colors (9 standard, 0 special edition): #1 Black; #3 Blue-Black; #11 Red; #21 Pink; #28 Violet; #30 Yellow; #41 Green; #57 Light Blue; #62 Brown.
- Per Platinum Japan (https://www.platinum-pen.co.jp/products/ink/2872/), checked 2026-11-02. Color numbers and names as Platinum Japan lists them, in English as Yoseka spells them. We have no color chips, so each swatch is a representative tint picked to match the name, not sampled from a photo. Shops stock different colors; check the listing.

## Key takeaways

- Platinum Japan lists SPN-100A as 2 cartridges per pack, 1.2 ml each, at ¥165 (about US$1.00) with tax.
- There are 9 colors: black, blue-black, red, pink, violet, yellow, green, light blue and brown, numbered #1 to #62.
- Platinum calls the ink water-based dye ink: #3 blue-black is acidic, #57 light blue is neutral, and the other seven are alkaline.
- The listed size is 38 × 7.5 × 115 mm (1.5 × 0.3 × 4.5 in) and a standard weight of 5.5 g.
- Yoseka's US listing is in our $ band, and on November 2, 2026 it showed yellow and brown as unavailable.

## What are Platinum SPN-100A cartridges?

**They are Platinum's standard short ink cartridges for its own fountain pens, sold two to a pack.** Platinum Japan's page files them under water-based dye ink for fountain pens, and lists the item code SPN-100A with a color number added.

Yoseka sells the same cartridges as "Platinum Ink Cartridges, pack of 2", with the SPN-100A code in its stock numbers. We read both pages on November 2, 2026.

## Platinum SPN-100A specs

| Spec | Value |
|---|---|
| Maker | Platinum Pen Co., Ltd., Japan |
| Code | SPN-100A plus a color number |
| Pack | 2 cartridges |
| Capacity | 1.2 ml each (0.04 fl oz) |
| Ink | Water-based dye ink |
| Listed size | 38 × 7.5 × 115 mm (1.5 × 0.3 × 4.5 in) |
| Standard weight | 5.5 g (0.19 oz) |
| Japanese list price | ¥165 (about US$1.00) with tax per pack |
| Price band | $ (under $5); Yoseka's US listing is inside it |

Platinum doesn't say whether the size is the pack or one cartridge. Its standard weight of 5.5 g fits a pack of two, so we read it as the pack.

## What colors do they come in?

**Nine: black, blue-black, red, pink, violet, yellow, green, light blue and brown.** Platinum numbers them #1, #3, #11, #21, #28, #30, #41, #57 and #62, with a seven-digit item number for each. Yoseka lists the same nine names.

Platinum labels the ink alkaline, except #3 blue-black, which is acidic, and #57 light blue, which is neutral. Our swatches are tints picked to match the names, not sampled from photos.

![Platinum SPN-100A pack drawn to scale: 38 mm wide and 115 mm tall from the front, 7.5 mm deep from the side](https://stationerytimes.com/images/platinum-spn-100a-ink-cartridges-pack.svg?v=42021dc3)

*One pack, front and side, at Platinum Japan's listed size. Original illustration made for this guide. © Stationery Times.*

## Which Platinum pens use SPN-100A?

**Platinum's own cartridge pens.** Our guides to the [Platinum Preppy](https://stationerytimes.com/guides/platinum-preppy/), [Plaisir](https://stationerytimes.com/guides/platinum-plaisir/), [Curidas](https://stationerytimes.com/guides/platinum-curidas/) and [#3776 Century](https://stationerytimes.com/guides/platinum-3776-century/) each say they take Platinum cartridges. Platinum's page labels the item for fountain pens and the CSIQ-150, a code we couldn't match to a product.

If you want bottled ink, a converter holds 0.53 ml by Platinum's figure, less than half a cartridge; see our [Platinum converter guide](https://stationerytimes.com/guides/platinum-fountain-pen-converter/). For a pigment cartridge, see [Platinum Carbon Black](https://stationerytimes.com/guides/platinum-carbon-black-ink/).


## How does a cartridge compare with Platinum's other ways to fill?

**Per milliliter the dye cartridges and the carbon pigment cartridges cost about the same in Japan, and a converter holds far less.** The figures below are from Platinum Japan, as quoted in our guides, with tax.

| Option | Ink per fill | Japanese list price |
|---|---|---|
| SPN-100A dye cartridges | 2 × 1.2 ml | ¥165 (about US$1.00) |
| SPC-200 carbon cartridges | 4 × 1.2 ml | ¥330 (about US$2.10) |
| Converter 800A | 0.53 ml | ¥990 (about US$6.30) |

Both cartridge packs work out near ¥69 (about US$0.40) a milliliter. The converter lets you use bottled ink, so its price buys freedom rather than volume.

## How acidic or alkaline is the ink?

**Seven colors are alkaline, #3 blue-black is acidic and #57 light blue is neutral, per Platinum.** Platinum doesn't explain the labels on the page. We don't know why the blue-black differs, and we haven't tested the ink's pH.

## Are all nine colors still sold?

**Platinum lists all nine, but Yoseka's stock was short.** On November 2, 2026, Yoseka showed yellow and brown as unavailable, and its stock code for brown carries a discontinued tag. Stock changes by shop, so check the shop you buy from.

## Where are they made, and what does it cost?

**Platinum doesn't say where they are made.** Its page gives no country and Yoseka's doesn't either, so we list it as not stated.

Platinum Japan lists ¥165 (about US$1.00) with tax for a pack of two, which is about ¥83 (about US$0.50) a cartridge. Yoseka's US listing, read on November 2, 2026, was US$3.50 a pack. We haven't compared shipping or fees.

## Frequently asked questions

### How much ink is in a Platinum SPN-100A cartridge?

Platinum Japan lists 1.2 ml per cartridge, with two cartridges in a pack.

### What colors do Platinum SPN-100A cartridges come in?

Nine: #1 black, #3 blue-black, #11 red, #21 pink, #28 violet, #30 yellow, #41 green, #57 light blue and #62 brown.

### Is Platinum SPN-100A ink acidic?

Platinum labels most colors alkaline. It lists #3 blue-black as acidic and #57 light blue as neutral.

### Is the ink waterproof?

Platinum calls it water-based dye ink and doesn't claim waterproofing on the page we read. Its carbon pigment cartridges are the ones sold for permanence.

### Which pens take SPN-100A cartridges?

Platinum labels it for fountain pens and the CSIQ-150, a model code we couldn't identify. Our guides say the Preppy, Plaisir, Curidas and #3776 Century take Platinum cartridges.

### Is the yellow or brown cartridge still sold?

Platinum Japan lists both. Yoseka showed yellow and brown as unavailable on November 2, 2026, and its stock code for brown carries a discontinued tag.

### Do these fit other brands' pens?

Not directly. Platinum pens take Platinum cartridges, and our Preppy guide notes that Platinum sells an adapter for standard international cartridges.

## Sources

- [Platinum Japan: SPN-100A water-based dye ink cartridges (2 per pack; 1.2 ml; ¥165; 38 × 7.5 × 115 mm; 5.5 g; nine colors and codes; acidity; read November 2, 2026)](https://www.platinum-pen.co.jp/products/ink/2872/)
- [Yoseka Stationery: Platinum Ink Cartridges, pack of 2 (nine colors with stock codes, yellow and brown unavailable; listed May 15, 2020; read November 2, 2026)](https://yosekastationery.com/products/platinum-ink-cartridges-pack-of-2)