The ingredients that make ink have been used for centuries in various capacities, allowing people to record history for future generations, or simply doodle. Pen ink ingredients vary based on the type of ink you are using.
Iron Gall Ink
This is an ink used by medieval scribes and requires a mix of strange and possibly toxic ingredients, so use it with care. The ink consists of iron sulphate, which can be found at drug stores as dietary supplements, tannic acid, which can be found on the bark of trees or brown rotting leaves, powdered gum arabic, which can be found in chemical supply stores and gallnuts, which can be ordered from online sources and crushed into a fine powder. The ink recipe consists of one part powdered gum arabic, two parts copperas, three parts crushed galls, and 30 parts water. This ink, sold in jars to dip the earliest quill pens, can still be found (and made) today.
Government Writing Ink
During the early 20th Century, the United States government devised a standard for ink for use in post offices. The ink is similar to many commercial writing inks. The formula was 11.7 grams of tannic acid, 3.8 grams of gallic acid crystals, 15 grams of ferrous sulphate crystals, 12.5 grams of a diluted hydrochloric acid, 12.5 grams of phenol acid, 1 gram of black dye and 1 liter of distilled water.
Different pens have their own unique ingredients of black ink, but there are widely-used ink mixtures similar to most of the black inks used in pens today. These authentic ingredients are not easy to find and have no substitutes. Pour one gallon of boiling water on 7 pounds of powdered galls, which are abnormal plant growths that you can purchase online. Then, let it sit in a warm area for two to three days. Add a half pound of green vitriol powder, stir the mixture with a wooden spatula and let it stand again for another two to three days. Boil five ounces of Arabic gum in a quart of boiling water and add to the mixture. Then strain it through a course linen cloth for use.