Diamine Ink

Diamine Ink Co has been mixing its ink in England since 1864, which makes it one of the oldest names in the game. It is a safe, water-based dye ink built specifically for fountain pens, so it flows cleanly through the nib and feed without the gum or shellac that would clog your pen. What makes it a favorite is the 100+ color range, from workhorse blue-blacks to deep sheening reds, at a price that lets you collect multiple. For most writers, it hits the sweet spot of reliable performance, good looks, and affordability.

The standard colors come in 30 mL and 80 mL bottles, and the same colors are also sold as packs of standard-international cartridges. The Shimmer line comes in its own 50 mL bottle, sized to leave headroom so you can mix the particles back into suspension by tilting or rolling the bottle. Between the bottle sizes and the cartridge packs, you can buy a color to sample it or stock up on your favorite.

Buy bottled ink if you want the full color range and the best value over time, and buy cartridges if you want grab-and-go convenience with no filling to manage. Bottles open up Diamine's entire standard palette plus the shimmer and special lines, they let you use a converter or a piston filler, and a single bottle will outlast a stack of cartridges. Cartridges win on portability and mess-free swaps, which is why they are the easy pick for a travel pen or a first fountain pen. Plenty of collectors keep both a bottle of the color they love and a few Diamine Cartridges for the pen that lives in a bag.

Diamine fountain pen ink is suitable for all fountain pen brands. It is a standard water-based, non-toxic dye ink with no unusual additives in the core range, so it won’t harm the nib, feed, or filling system. Transfer it from the bottle into any converter, piston, or vacuum filler and you’re good to go, whatever brand of pen you own. The one thing to check is not the pen brand but the cartridge fit, which is the next question.

Diamine cartridges fit any pen that takes a standard-international short cartridge. This size covers most of the market, including Kaweco, Waterman, Faber-Castell, Pelikan, and Monteverde. The pens that will not fit are the ones with proprietary cartridges, most notably Lamy, Pilot, Sailor, and Platinum, which each use their own shape. If you aren’t sure which camp your pen is in, our cartridge and converter compatibility guide lays it out brand by brand.

Shimmer inks have fine, pearlescent particles suspended in them, rendering a glint that catches the light as it dries. Because those particles settle at the bottom of the bottle, the trick is to roll or gently shake the bottle before every fill so the shimmer is evenly mixed, then give the pen an occasional turn as you write. Pair a shimmer ink with a medium or broader nib so the particles have room to flow, since a very fine nib can hold them back. If you know you’re drawn to shimmer, you can focus your search on the Diamine Shimmer Bottled Ink collection.

A shading ink varies in the depth of its own color, pooling darker where the ink gathers and staying lighter where the strokes are thin, so a single color reads as a soft gradient. Diamine's Earl Grey, for example, is a well-loved shader. Meanwhile, a sheening ink dries with a second, contrasting color that glints on the surface, like the vivid red sheen that lifts off Diamine Majestic Blue. Shading lives inside the color, sheen sits on top of it, and both show best on ink-friendly paper with a wet nib.

The Diamine Inkvent, Guitar, and 150th Anniversary editions are special and limited releases that feed the collector’s chase. Inkvent is Diamine's advent-style collection, including Blue, Green, Red, and Teal editions, each a run of distinct inks built to be discovered one at a time. The Guitar range is inspired by famous Gibson Les Paul guitars, and the 150th Anniversary line marks Diamine's 1864 founding with 40 mL wedge-shaped bottles that form a wheel once 8 are set together.

Diamine's standard inks are not waterproof. They are water-based dye inks, so a splash or a damp thumb can smear or lift the color off the page, though often a darker, more saturated color holds up better than a bright wash. If you need your writing to survive water, look for an iron gall ink that bonds to the paper as it dries, such as the waterproof Diamine's Registrar’s ink, or browse our water-resistant options.

First, flush the nib and feed with cool water until it runs completely clear. Then, rinse it a few more times than you would a plain ink. Shimmer particles and densely saturated dyes settle into the feed's channels, so if you can unscrew your pen, take the nib and feed apart and clean the shimmer out of the fins, too. For stubborn residue, a drop of pen flush or heavily diluted dish soap in the water helps, followed by a clean-water rinse. The rule of thumb with shimmer is to write with it frequently, since a pen in use keeps the particles moving. If you’d like a walkthrough, our How to Clean a Fountain Pen guide covers each step thoroughly.

For a beginner, reach for a well-behaved and classic blue-black like Midnight Blue, a true blue like Oxford Blue or Sapphire Blue, or a solid Jet Black. These colors flow easily, dry at a sensible pace, and show a touch of Diamine's character. They also ask little more than a rinse of you at cleaning time. Once you’re comfortable filling and flushing a pen, that’s when the fun of sheens and shimmers really starts! Begin with a color you know you’ll use every day and let your collection grow from there.