Oak galls and iron(II) sulfate, ingredients of iron gall ink

Iron gall ink (sometimes iron gall nut ink) is a purple-black ink made from iron salts and tannin from vegetable sources. It was the standard writing and drawing ink in Europe, from about the 12th century to the 19th century, and remained in use well into the 20th century. Species See List of Quercus species The term oak can be used as part of the common name of any of several hundred species of trees and shrubs in the genus Quercus, and some related genera, notably Cyclobalanopsis and Lithocarpus. ... Kalanchoë infected with crown-gall using Agrobacterium tumefaciens. ... Iron(II) sulfate (IUPAC-recommended spelling; also sulphate in British English), also known as ferrous sulfate (FeSO4) is an ionic compound. ... General Name, Symbol, Number iron, Fe, 26 Chemical series transition metals Group, Period, Block 8, 4, d Appearance lustrous metallic with a grayish tinge Atomic mass 55. ... Tannins are astringent, bitter-tasting plant polyphenols that bind and precipitate proteins. ... An ink is a liquid containing various pigments and/or dyes used for colouring a surface to render an image or text. ... World map showing Europe A satellite composite image of Europe Europe is one of the seven traditional continents of the Earth. ... (11th century - 12th century - 13th century - other centuries) As a means of recording the passage of time, the 12th century was that century which lasted from 1101 to 1200. ... Alternative meaning: Nineteenth Century (periodical) (18th century — 19th century — 20th century — more centuries) As a means of recording the passage of time, the 19th century was that century which lasted from 1801-1900 in the sense of the Gregorian calendar. ... (19th century - 20th century - 21st century - more centuries) Decades: 1900s 1910s 1920s 1930s 1940s 1950s 1960s 1970s 1980s 1990s As a means of recording the passage of time, the 20th century was that century which lasted from 1901–2000 in the sense of the Gregorian calendar (1900–1999...

Preparation and use

Homemade ink. On left, solution of iron (from nails) and vinegar. On right, oak extraction. The two are mixed immediately prior to use to produce the ink, center.

The ink was generally prepared by adding some ferrous sulfate (FeSO₄) to a solution of tannin (gallotannic acid). The latter was usually extracted from oak galls (also known as "oak apples"), or galls of other trees; hence the name. Fermentation or hydrolysis of the extract releases gallic acid, which yields a darker black ink. The fermented extract is combined with the ferrous sulfate and a binder such as gum arabic. Vinegar is sometimes infused with spices or herbs—as here, with oregano. ... Iron(II) sulfate (FeSO4) is an example of an ionic compound. ... General Name, Symbol, Number iron, Fe, 26 Chemical series transition metals Group, Period, Block 8, 4, d Appearance lustrous metallic with a grayish tinge Atomic mass 55. ... General Name, Symbol, Number sulfur, S, 16 Chemical series nonmetals Group, Period, Block 16, 3, p Appearance lemon yellow Atomic mass 32. ... General Name, Symbol, Number oxygen, O, 8 Chemical series Nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance colorless (gas) very pale blue (liquid) Atomic mass 15. ... Tannins are astringent, bitter-tasting plant polyphenols that bind and precipitate proteins. ... A bottle of tannic acid. ... Species See List of Quercus species The term oak can be used as part of the common name of any of several hundred species of trees and shrubs in the genus Quercus, and some related genera, notably Cyclobalanopsis and Lithocarpus. ... Kalanchoë infected with crown-gall using Agrobacterium tumefaciens. ... An oak apple is a mutation of an oak leaf caused by chemicals injected by the larvae of certain kinds of gall wasp. ... Fermentation in progress Fermentation typically refers to the conversion of sugar to alcohol using yeast. ... Hydrolysis is a chemical reaction or process in which a molecule is split into two parts by reacting with a molecule of water, which has the chemical formula H2O. One of the parts gets an OH- from the water molecule and the other part gets an H+ from the water. ... Chemical structure of gallic acid Gallic acid is an organic acid, also known as 3,4,5-trihydroxybenzoic acid, found in gallnuts, sumac, witch hazel, tea leaves, oak bark, and other plants. ... Acacia senegal plant from Koehlers Medicinal-Plants 1887 Gum arabic, a natural gum also called gum acacia, is a substance that is taken from two sub-Saharan species of the acacia tree, Acacia senegal and Acacia seyal. ...

After filtering, the resulting pale-gray solution was used to write on paper or vellum. A well-prepared ink would gradually darken to an intense purplish black. The resulting marks would adhere firmly to the vellum or parchment, and (unlike india ink or other formulas) could not be erased by rubbing or washing — only by actually scraping off a thin layer of the writing surface. Paper is a thin material produced by the amalgamation of fibres, typically vegetable fibers composed of cellulose, which are subsequently held together by hydrogen bonding. ... Vellum (from the Latin for wool or pelt) is a sort of parchment, a material for the pages of a book or codex, characterized by its thin, smooth, durable properties. ... Indian ink (or India ink in American English) is a simple black ink once widely used for writing and printing. ...

That it *can* be completely removed was sufficient to allow this ink, or a galloferric ink with added carbon black, (lamp black) to be used in making Torah scrolls - if a letter is ever found cracked, common with a vellum document rolled and rerolled daily, it must be removed in its entirety before it is redrawn for the scroll to remain ritually pure. This has apparently led to many a "red" Torah, where leaves of vellum have, over the years, faded to a still perfectly legible red, harbinger of future destruction^{[citation needed]}. Sefer Torah being read during weekday service. ...

Chemistry

Homemade iron gall ink in use, displaying the delayed darkening of the ink.

The gradual darkening of the ink was due to the oxidation of the iron ions from ferrous (Fe²⁺) to ferric (Fe³⁺) state by atmospheric oxygen. (For that reason, the liquid ink had to be stored in a well-stoppered bottle, and would become unusable after a time.) The ferric ions then reacted with the tannin or some derived compound (possibly gallic acid or pyrogallol) to form a polymeric organometallic compound. The gallol would then make strong and permanent chemical bonds with the proteins of the hide, by the same chemical processes underlying tanning. The most fundamental reactions in chemistry are the redox processes. ... Ferrous in chemistry is a term used for the iron with an oxidation number +2. ... Ferric is a term used for the iron with the oxidation number +3. ... General Name, Symbol, Number oxygen, O, 8 Chemical series Nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance colorless (gas) very pale blue (liquid) Atomic mass 15. ... Pyrogallol or benzene-1,2,3-triol is a white crystalline powder and a powerful reducing agent. ... Polymer is a term used to describe large molecules consisting of repeating structural units, or monomers, connected by covalent chemical bonds. ... An organometallic compound is partially characterized by the presence of one or more metal-carbon bonds, in which the carbon involved would, apart from the metal-carbon bond, be otherwise considered a part of an organic compound. ... Tanning is the process of conversion of putrescible skin into non putrescible leather. ...

While a very effective ink on vellum, the formula was less than ideal for paper, since the iron-tannin pigment would not make chemical bonds with the cellulose fibers. The ink still stuck firmly to the paper, but largely by mechanical bonding — namely the dried ink would penetrate the spaces between the fibers and, after drying would become entangled in them. Besides causing unsightly "ghost writing" on the obverse face of the paper, any excess of ferrous ions remaining by the ink, over years or decades, would create a rusty halo around the marks, and would ultimately cause the paper to disintegrate. Cellulose as polymer of β-D-glucose Cellulose in 3D Cellulose (C6H10O5)n is a long-chain polymeric polysaccharide carbohydrate, of beta-glucose [1][2]. It forms the primary structural component of green plants. ...

Demise

The permanence and water-resistance of the iron and gall-nut formula made it the standard writing ink in Europe for over 700 years. Its use only started to decline in the 20th century, when other water-proof formulas (better suited for writing on paper) became available. Nowadays, iron gall ink is manufactured chiefly by artists enthusiastic about reviving old methods. (19th century - 20th century - 21st century - more centuries) Decades: 1900s 1910s 1920s 1930s 1940s 1950s 1960s 1970s 1980s 1990s As a means of recording the passage of time, the 20th century was that century which lasted from 1901–2000 in the sense of the Gregorian calendar (1900–1999...

Warning

Iron gall ink is not suitable for fountain pens as it will corrode them very quickly. Instead one should use modern surrogate formulas such as Montblanc blue-black, which has a very small amount of the ferro gallic compounds, or Rohrer & Klingner "Scabiosa" and "Salix" inks, both of which require the fountain pen to be flushed out regularly with water. A fountain pen is a writing instrument, more specifically a pen, that contains a reservoir of water-based ink that is fed to a nib through a feed via a combination of gravity and capillary action. ... Montblanc International GmbH is a German manufacturer of fine writing instruments, watches and accessories, often identified by their famous White Star logo. ...

See also

• Indian ink
• Alizarine ink
• Pen and ink

Indian ink (or India ink in American English) is a simple black ink once widely used for writing and printing, and now more commonly used for drawing, especially when inking comics. ... The following is a recipe for Alizarene ink taken from the Household Cyclopedia of General Information, [1] which was published in 1881. ... Pen and ink refers to a technique of drawing or writing, in which colored (this includes black) ink is applied to paper using a pen or other stylus. ...

External link

• How to make iron gall ink, at an ink corrosion website.