万年筆インクノート｜在庫と色見本

Fountain pen ink isn't something you look up once and forget. How many bottles of each color you own, what ink you've put in each pen, how that color actually looks when you write with it—it's a unique record that changes with each pen you own. Searches and catalogs won't remember your inventory, the colors currently in your pens, or the color samples you've drawn yourself.

Fountain Pen Ink Notebook is a record-keeping app for fountain pen inks that brings together your ink inventory, currently used colors, and your homemade color samples in one place.

■ Pre-Buy Check (The core of this app)
Even before registering an ink, you can try judging it using three sample inks from "View Pre-Buy Check Samples" on the home screen (the samples are not saved). Immediately after registering your first ink, it displays three variations of that color—different in brightness and shade—on a single screen, showing you whether each would be judged as "almost the same/similar/different" if you saw them in a store. If you're in a store and think, "Do I already have this color?", open "Pre-Buy Check" on the home screen and select a color similar to the one you're thinking of buying. Pressing one of the top color family chips (blue/blue-black/black, etc.) will immediately tell you how many bottles of that family you own, and the table below will list the ink names and remaining percentages (e.g., "I have two blue bottles" will be followed by Iroshizuku Konpeki and Iroshizuku Asagao, along with their respective remaining amounts). The app categorizes colors by family, so dark blues (like Iroshizuku Shinkai) will be categorized under blue-black. Since family alone doesn't tell you if they're the same color, we won't say "almost the same" here. After selecting from the palette, you can fine-tune the brightness and saturation of the same color in a 5x5 grid. You can also search for "something similar" from your existing ink color samples. When you match colors, the result appears at the top of the screen, and the top 3 closest color samples from your collection are displayed side-by-side as "almost the same/similar/different" (it compares colors based on how the human eye perceives them, so it can distinguish between similar blues). If you enter an ink name, it will also show if you already own that ink, and if so, how much is left (percentage and how many more refills are possible). Once purchased, it can be registered directly in your inventory.

The inventory list allows you to search by brand, ink name, and color name, and also filter by color family (blue/green, etc.).

■ Current Colors in Each Fountain Pen and Washing Notifications
The home screen displays which ink is in each fountain pen and how many days have passed since the ink was added. The washing interval varies depending on the ink (dye-based inks are set to 30 days by default; classical, pigment, and glitter inks are prone to clogging, so 14 days). You will be asked only once, when you first add ink, whether you want to receive a washing notification. If you select "Notify," you will receive a notification two days before and on the day it's time to wash your pen, including the pen and ink names and the number of days remaining, such as "Custom 74 with Iroshizuku Konpeki ink, 28 days. Washing in 2 days." Notifications will not be sent on days when there are no corresponding pens.

You can record the pens you wrote with on that day by tapping "Written" on the home screen. When you tap it, the "Approximately ◯ days until ink runs out" at the right end of that line decreases by one, and the days you wrote with the pen in the last 7 days are filled in with dots (the total number of days you've written this month is displayed in "Monthly Review" on the home screen). When changing ink or cleaning, if you select "Previous ink was used up / still had ink left," the system will remember the number of days you wrote with each pen until it ran out, and from the next time onwards, it will also display "Approximately ◯ uses left before ink runs out." This counts even if you change colors. Until you've finished writing with the same pen, it will show "Approximately ◯ days left until ink runs out" based on the pen's ink level, and this number will decrease by one each time you press "Written," so the number will change from the day you started using it (both are estimates based on records). The number of days until ink runs out will be adjusted according to your writing style, which you can choose from "How much do you write per day?" (a few lines of notes/one sheet of stationery/a few pages of notebook) in the pen details. Days you forgot to write on can be added later in "Days written this past week" in the pen details. You can also select the date you refilled the ink up to 7 days ago. At the far right of each pen's row on the home screen, it will show "Approximately ◯ days until ink runs out" using the same ruler (pens where you haven't yet chosen your writing amount will have "(tentative)" next to it, and you can choose it on the spot when you press it), pens that are nearing the time to wash will have "◯ days left until washing" added, and the color of the number will change for pens that haven't been written on for 3 days. The last row of the pen list will show the next pen that needs washing and the date. On the 7th day after filling with ink, you'll receive a notification once indicating the remaining days until it's time to wash the pen (if notifications are turned on). "Number of refills this month, writing dates, and most used color" are updated daily on the home screen.

■ Custom Color Swatch
By selecting and registering colors similar to those you've actually written with, you'll create your own personalized color swatch, displaying your inks in hue order. Even the same ink can look different depending on the paper and nib. Having your own color swatch helps when choosing ink next time and avoids buying similar colors.

■ Remaining Amount and "How Many More Refills"
By entering the bottle capacity and the amount of ink used per refill for each pen (converter/cartridge capacity), the system will subtract that amount each time you refill, displaying the remaining amount and "how many more refills are possible" in the inventory list and ink details. Ink that's running low will be marked as "time to refill" on the home screen and inventory list (no notification). You can also measure and adjust the remaining amount.

■ Calendar and Summary
The dates you refilled and cleaned your pens are marked on the calendar. The summary allows you to review monthly refill counts, frequently used inks, the number of pens by color and brand, and the total value of your collection (including prices).

■ The Basics of Fountain Pen Ink
Includes information on the differences between dye, pigment, and traditional inks, cartridges and converters, cleaning timing and methods, storage and ink lifespan, how to deal with skipping ink, and how to create color samples, all with sources cited.

■ What it Can't Do (Listed First)
- There is no function for selling or mail-ordering inks or fountain pens. This is purely an app for recording your own collection.
- The remaining ink level is an estimate based on "refill record × pen ink volume." Please measure and correct the accurate remaining amount.
- The pre-purchase color check is a comparison of colors selected using the on-screen palette or color code. There is no function to read colors from photos.
- There is no automatic synchronization across devices. Records are saved only on the device used for input.

■ Things It Doesn't Collect
There is no account registration or login. All ink and fountain pen records, photos, and settings are stored solely on your device and are never sent to external servers. Banner ads (AdMob) are displayed at the bottom of the list and home screens to cover operating costs, but the records and photos you enter will never be used for advertising. Uninstalling the app will erase your records, so it's a good idea to keep important photos in your device's photo album as well.

*The manufacturer and product names appearing in the images and records are trademarks of their respective companies. This app is a personal ink recording app and is not affiliated with or affiliated with any manufacturer.

Start by registering your favorite ink. Each time you buy a new ink, fill a pen with it, or add a color sample, your unique ink notebook will grow.