Inktend / Pen library / Delrin
Gravitas
Delrin
A model in Gravitas's fountain pen lineup. Specs below reflect the typical configuration across Gravitas's core range.
A solid mid-range option once someone has decided fountain pens are a habit worth investing a bit more into.
Specs
About Gravitas
Gravitas Pens was started in 2015 by Irish industrial designer Ben Walsh, initially under the name Ben Walsh Design making concrete pens before moving to precision-machined metal designs. The range is built around heavy machined bodies in stainless steel, brass, titanium, copper alloys, zirconium and carbon fibre, with models including the Entry, Sentry, Pocket, Flagship, Piston and Vac. In 2024 the company relocated operations to Romania through a partnership with Pen Venture; pens use standard #6 and #8 nibs and span roughly €50 to €620.
How to fill the Gravitas Delrin
Unscrew the piston knob at the back of the pen, submerge the nib fully in a bottle of ink, and slowly turn the knob counter-clockwise then clockwise to draw ink in. Piston fillers hold significantly more ink than a standard cartridge — often enough for several weeks of regular writing — at the cost of being limited to bottled ink only.
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. The Delrin's gold nib will also flex slightly with pressure, giving line variation that a steel nib of the same size won't produce.
Keeping it clean
Because Gravitas Delrin holds a larger ink reserve, a full flush every 4–6 weeks (or whenever you switch colors) keeps the feed running cleanly. Inktend's cleaning reminder is tuned to a 21-day baseline and adjusts naturally to how often you actually refill.
Pairing inks with the Delrin
High-capacity fillers like this one are the natural home for sheening and shading inks; you'll actually see the color develop across a full page instead of running out mid-paragraph.
Frequently asked questions
More from Gravitas
Specs reflect the typical configuration across Gravitas's core lineup rather than this exact model — check current listings before buying.