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The Good Blue

R615 Fountain Pen

Typical for The Good Blue
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A model in The Good Blue's fountain pen lineup. Specs below reflect the typical configuration across The Good Blue's core range.

A solid mid-range option once someone has decided fountain pens are a habit worth investing a bit more into.

Specs

Filling systemCartridge / converter (typical for most fountain pens)
Ink capacityVaries by model
Nib optionsF, M (steel, typical)
MaterialResin or metal
Typical priceVaries — check current listings
How long has your R615 Fountain Pen been inked?
Inktend counts the days and reminds you when it's time to clean.
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About The Good Blue

The Good Blue is a small London-based startup founded by a maker named Sunil, whose first flex fountain pens appeared in 2021. Its CNC-machined aluminum and brass pens, the R615 and L130, pair flexible stainless steel, titanium, or 14k gold nibs with a specially designed high-flow feed produced by UK laser sintering, and the pens are manufactured in the UK. The brand is known for bringing usable flex-nib writing to everyday pens for calligraphy, sketching, and journaling.

United Kingdom Founded —
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How to fill the The Good Blue R615 Fountain Pen

Fill it two ways: snap in a pre-filled international cartridge for convenience, or use a converter — a small plunger or twist mechanism that installs the same way a cartridge does — to draw ink from any bottle. The converter route opens up the entire world of bottled ink, which is where most of the hobby's color variety lives.

Choosing a nib size

Nib size determines line width, not writing pressure — fountain pens are meant to glide, never press. Extra-fine (EF) suits small, dense handwriting and thin paper; fine (F) is the most broadly recommended default; medium (M) shows more ink character and shading; broad (B) and stub grinds favor bold, expressive strokes and calligraphy-adjacent writing.

Keeping it clean

A quick flush with cool water every time you switch ink colors — and a full clean every 4–6 weeks of regular use — is enough to keep the nib and feed performing well. Inktend's cleaning reminder is tuned to a 21-day baseline and adjusts naturally to how often you actually refill.

Pairing inks with the R615 Fountain Pen

Because refills are quick with a cartridge or converter, this is a good pen for rotating through several colors rather than committing to one; sample vials work especially well here.

Shading Chromatography - Lagoon
Malevich
Wixarica - Kauyumari
Monarca
Turquoise
Monteverde

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Frequently asked questions

How do I fill the The Good Blue R615 Fountain Pen?
Snap in a pre-filled cartridge, or use a converter to draw ink from any bottle. The converter route is the cheaper long-term option.
What nib size should I get for the R615 Fountain Pen?
Fine (F) is the safest default for a first pen. Go finer for small, dense handwriting; go broader if you want more ink character and shading.
How often does the R615 Fountain Pen need cleaning?
Flush it each time you switch inks, and give it a full clean every 4 to 6 weeks of regular use.
Is the The Good Blue R615 Fountain Pen good for beginners?
It can work as a first pen if you're comfortable spending a bit more to start.

More from The Good Blue

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L130
The Good Blue

Specs reflect the typical configuration across The Good Blue's core lineup rather than this exact model — check current listings before buying.