"Kelp Forest" by Robert Oster - Fountain Pen Ink Review - Light Green

Jul 1
4 min read

Robert Oster Kelp Forest is a captivating light green ink with surprising shading qualities.

🖋 Core Properties

✅ Standard Fountain Pen Ink

❌ Waterproof/Permanent Ink

The Review:

After putting Robert Oster’s Kelp Forest ink through daily testing for over two weeks across three different pen and nib combinations, I found it to be a genuinely fun and high-performing ink with remarkable shading properties. The ink features a gorgeous dual-color aesthetic: a rich green base that shades beautifully into warm undertones of brown and gold. While you can still catch glimpses of this beautiful transition using a fine nib, the shading truly steals the show when paired with medium or broad nibs. The ink boasts an excellent, smooth flow with zero issues regarding skipping or clogging. As a bonus for those who like to rotate colors frequently, it is a lighter-colored ink that cleans out of pens effortlessly without leaving a single trace of staining.

However, because Kelp Forest is a wet-flowing ink that is neither waterproof nor water-resistant, its performance is heavily dictated by your choice of pen and paper. When paired with a fine nib on standard 75g copy paper, it behaves admirably with no feathering or bleeding. But once you move up to broader, wetter writers—like a medium-nib Conklin Duragraph—standard paper will struggle with ghosting and bleed-through. Furthermore, dry times vary drastically depending on your setup, ranging from a quick 8 seconds in a finer pen to upwards of 50 seconds in a very wet medium nib, which left-handed writers will want to keep in mind. Ultimately, if you love dynamic shading and don't mind pairing it with quality fountain pen paper and managing the dry times, Kelp Forest is a standout performer; but if you strictly use fine nibs and cheap copy paper, it might not be the best match for your needs.

To bring the review to life, I’ve included a series of photographs that demonstrate the ink’s behavior under real writing conditions. These images highlight everything from smudge resistance and drying time intervals to the flow characteristics observed during extended writing. You are seeing my authentic comments penned using the ink itself, offering a direct glimpse into its consistency, saturation, and personality of the ink. These snapshots serve not just as proof, but as part of the ink’s narrative—capturing its strengths, quirks, and overall impression.

**Please note that our reviews may differ significantly from what you typically see from other individuals or companies. This is more than just a review—it's an ink test conducted for both our benefit and yours. We use each ink for one and a half to two weeks to gather as much information as possible. During this time, we test a range of nib sizes to evaluate how the ink performs across different writing styles. Some inks are tested with everything from a fine nib to a 1.1 mm stub, while shimmer inks may only be used with broad and stub nibs, as we generally advise against using shimmer inks with fine or extra-fine nibs.

This isn’t a “sit down, open a bottle, and write a review in 15 minutes” kind of approach. Instead, we aim to offer insights based on real-world tests and extended daily use. Keep in mind, every pen writes a little differently, and ink performance can vary from one to another. We also conduct several tests on various types of paper. Most of the time, we use Clairefontaine Triomphe 90g paper as our high-quality benchmark, and Pen+Gear 20lb copy paper as a lower-quality comparison.**

Performance Factors

Saturation & Depth - (How rich and bold the ink appears)

4 Nibs (✒️✒️✒️✒️✧) – Deep, rich tones! Pops off the page beautifully.

Shading / Sheen / Shimmer - (How the ink performs against other inks in this category)

4 Nibs (✒️✒️✒️✒️✧) – Beautiful shading/sheen/shimmer! Ink has depth and personality.

Consistency & Flow - (Is is smooth & reliable while writing?)

4 Nibs (✒️✒️✒️✒️✧) – Smooth & steady. Reliable, no skips, great ink performance.

Feathering & Bleed-through - (How much the ink spread/bleed on different paper types)

4 Nibs (✒️✒️✒️✒️✧) – Excellent! No feathering on quality paper.

Drying Time - (How fast the ink dries on paper?)

2 Nibs (✒️✒️✧✧✧) – Sluggish. Takes 21-30 seconds depending on the nib, risky for left-handers.

Smudging & Smear Resistance - (How well the ink resists smudging)

5 Nibs (✒️✒️✒️✒️✒️) – Smudge-proof! Once dry, it won’t budge at all.

Water Resistance - (How well the ink holds up against moisture)

2 Nibs (✒️✒️✧✧✧) – Mostly dissolves. Some traces remain, but not legible.

Cleaning - (How easy it is to flush ink from a fountain pen?)

4 Nibs (✒️✒️✒️✒️✧) – Quick flush. Minimal effort needed—leaves no stubborn traces.

Staining – (Does the Ink Leave a Mark Where It Shouldn't after cleaning?)

4 Nibs (✒️✒️✒️✒️✧) - Little to no staining visible. Feed may retain faint traces, but barrel and nib clean easily.

Overall Opinion

Kelp Forest by Robert Oster is a pleasure to use. Beautiful color, good flow, and just enough uniqueness to elevate your writing. Not quite perfect, but it rewards regular use and offers a refined experience without fuss.

Interested in this ink?

Robert Oster Fountain Pen Ink 50ml - Forest Kelp - Standard Ink

$18.00$14.40

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