Artists and sketchers have different requirements from fountain pen inks than everyday writers do. The ink needs to serve the image — either by staying put under wet media applied over it, or by dissolving into watercolour-like washes when worked with a damp brush. Both approaches are valid; both require specific inks. This guide covers both, with recommendations for each technique.
Approach one: waterproof linework
Sketch in ink; apply watercolour or ink washes over the top without disturbing the lines. This is the traditional approach — the linework is the permanent underdrawing, and colour is added later. For this to work, the sketch ink must be waterproof once dry.
Platinum Carbon Black — The most widely used waterproof fountain pen ink for sketching. Pigment-based, archival quality, fully waterproof once cured. The resulting line holds up to wet watercolour, markers, and even re-wetting the page. Requires a pen with easily removable nib and feed (TWSBI, LAMY Safari, Kaweco Sport) because pigment inks must be cleaned regularly to prevent clogging. Clean every one to two weeks minimum.
De Atramentis Document inks — A range of waterproof document inks in colours beyond just black. The Document range includes blue, sepia, and other colours that hold firm under water — useful for artists who want to sketch in something other than black ink and still apply wet media over the top. Fast-drying, exceptionally waterproof.
Approach two: water-soluble washes
Sketch in ink; brush clean water over the lines to dissolve and spread the ink into graduated washes. The line acts as both an outline and a pigment source. Water-soluble dye inks are required for this technique — the same inks you'd normally use for everyday writing, applied with a sketching eye.
Pilot Iroshizuku Take-sumi — A rich, dark black that produces beautiful warm-grey washes when diluted with water. The most popular Iroshizuku colour for sketching because the dark ink provides both strong linework and generous wash tone. A single colour does the work of a full tonal range.
Diamine Ancient Copper — A rust-orange ink that shades dramatically and produces spectacular wash effects when worked with a damp brush. From deep orange-rust through pale amber to almost transparent warmth, the wash range is wide. Excellent for botanical illustration and warm, earthy sketching.
Pilot Iroshizuku Yu-yake — A sunset orange-red that produces warm wash gradients. Artists use this for warm-toned sketches where the ink alone conveys light and atmosphere through its tonal range.
Diamine Grey — For ink wash effects specifically: Diamine Grey's low water resistance and neutral tone make it the most useful grey for wash techniques. Applied thickly it reads as a mid-grey; diluted it produces soft, graduated tones useful for shading and atmospheric effects.
Using coloured inks for sketching
Sketching with coloured inks rather than black opens expressive possibilities that monochrome linework doesn't have. A blue-grey line for cool, architectural subjects; a warm copper for organic botanical work; a dark teal for atmospheric urban sketching. Any water-soluble Iroshizuku or Diamine ink can be used for wash-based sketching — the choice of colour becomes part of the artistic decision rather than a neutral starting point.
Recommended pens for sketching
For waterproof inks: pens with easily removable nib and feed for thorough cleaning. TWSBI ECO, LAMY Safari, Kaweco Sport are all popular choices. Avoid pens with permanently fixed nib units for regular pigment ink use.
For water-soluble sketching: any well-maintained fountain pen works. Many sketchers use the same pen they write in daily — there's no need for a dedicated sketch pen when using standard dye inks.
Browse artist-suitable fountain pen inks at The Journal Shop, including Pilot Iroshizuku, Diamine, and Platinum Carbon Black.
Where to start: browse our fountain pen inks and fountain pens at The Journal Shop.
