Making Lampblack Pigment — Collecting Carbon Soot from a Burning Flame

Pour 100-200 ml of vegetable oil (linseed, sesame, or rapeseed) into a shallow clay dish or metal bowl. Make a wick from twisted cotton cord or cotton fabric strip. Place the wick in the oil with one end extending over the rim. Light the wick and adjust it to produce a small, steady, smoky flame — a short wick gives more smoke (incomplete combustion). Position a ceramic plate or metal sheet 3-5 cm above the flame tip where the soot is densest.

Let the lamp burn steadily for 30-60 minutes. The soot deposits as a velvety black layer on the underside of the collection surface. When a thick layer has accumulated (1-2 mm), carefully remove the plate and scrape the soot into a clean container using a palette knife or the edge of a stiff card. Replace the plate and continue collecting. Work in a well-ventilated area — the smoky flame produces carbon monoxide. For a full session, expect to collect 5-15 g of lampblack from 200 ml of oil.

Raw lampblack contains trace oils and tar from incomplete combustion. To purify, place the collected soot in a small container and add a little warm water. Stir to form a slurry. Let the heavy impurities settle for a few minutes, then carefully pour off the black suspension into a second container — this contains the fine pigment particles. Let the suspension settle overnight. Pour off the clear water and allow the pigment to dry completely. This levigation step removes gritty particles and oily residues.

Once dry, the lampblack will be a soft, fluffy mass. Grind it with a mortar and pestle or on a glass slab with a glass muller to break up any lumps. Lampblack is already extremely fine, so this step is mostly about achieving uniformity. The finished pigment should feel silky and leave an intense black mark when rubbed between your fingers. Store in a sealed jar away from moisture. This pigment is ready to mix with any binder — oil, egg yolk, gum arabic, hide glue, or lime water.