Making Bistre Ink from Wood Soot — The Warm Brown Drawing Ink of Old Masters

Scrape soot from the inside of a chimney, stove flue, or fireplace that has been burning hardwood (beech, birch, oak, or ash). The soot should be the soft, brownish-black deposit that accumulates on the inner walls — not the hard, glossite creosote deposits (which are too tarry). Chimney soot from hardwood fires contains a mixture of carbon particles and water-soluble tarry compounds that give bistre its characteristic warm brown colour. Collect approximately 50-100 g. Softwood soot (pine, fir) can also be used but produces a darker, more reddish-brown ink due to higher resin content.

Place the collected soot in a glass beaker and add approximately 5 parts water to 1 part soot. Bring to a gentle boil and simmer for 30-60 minutes, stirring occasionally. The water turns a deep golden-brown to dark chocolate-brown as the soluble tar compounds dissolve. The carbon particles do not dissolve — they remain suspended as black specks. Longer boiling extracts more colour. After simmering, remove from heat and let cool slightly.

Strain the brown liquid through fine cheesecloth or cotton cloth into a clean jar. The cloth catches the insoluble carbon particles and any grit, leaving a clear, deep golden-brown to chocolate-brown liquid. This filtered liquid IS bistre — the colour comes entirely from the dissolved organic compounds, not from suspended carbon. If the liquid is very dark, dilute with water to your preferred strength. For a more concentrated ink, let the filtered liquid evaporate partially by leaving it uncovered in a warm place.

For use as a drawing ink, add a small amount of gum arabic — approximately 5-10% by weight of the liquid — and stir until dissolved. The gum arabic acts as a binder, giving the ink body, improving its flow from pen or brush, and helping it adhere to paper. Without gum, bistre tends to be thin and slightly fugitive on paper. With gum, it produces rich, warm washes and clean pen lines. For watercolour-style washes, the ink can be diluted further with water — bistre is beautifully transparent and produces a wide range of warm tones from pale gold to deep brown.

Store the finished bistre ink in a tightly sealed glass jar. The ink keeps for months if sealed. Over time, some sediment may form — shake or stir before use. If mould develops (the organic compounds can support microbial growth), add a drop of clove oil as a preservative. Bistre is at its best as a wash medium for drawing: load a brush, touch it to dampened paper, and the warm brown colour flows and blooms beautifully. For pen drawing, use with a quill or reed pen. The characteristic warm golden-brown tone of bistre is immediately recognisable in Old Master drawings — it has a warmth and transparency that neither carbon ink (too cool) nor iron gall ink (too grey-black) can match.