India ink

Basic India ink is composed of a variety of fine soot, known as lampblack, combined with water to form a liquid. No binder material is necessary: the carbon molecules are in colloidal suspension and form a waterproof layer after drying. A binding agent such as gelatin or, more commonly, shellac may be added to make the ink more durable once dried. India ink is commonly sold in bottled form, as well as a solid form as an inkstick (most commonly, a stick), which must be ground and mixed with water before use. If a binder is used, India ink may be waterproof or non-waterproof. Artist pens that contain India ink, use an acrylic based binder rather than shellac. == History ==

used for the preparation of ink Woods and Woods (2000) state that the process of making India ink was known in China as early as the middle of the 3rd millennium BC, in Neolithic China, whereas Needham (1985) states that inkmaking commenced perhaps as early as 3 millennia ago in China. India ink was first invented in China, but the English term India(n) ink was coined due to their later trade with India. India ink has been in use in India since at least the 4th century BC, where it was called masi, an admixture of several substances. Indian documents written in Kharosthi with this ink have been unearthed in as far as Xinjiang, China. The practice of writing with ink and a sharp-pointed needle in Tamil and other Dravidian languages was common practice from antiquity in South India, and so several ancient Buddhist and Jain scripts in India were compiled in ink. In India, the carbon black from which India ink is produced is obtained by burning bones, tar, pitch, and other substances. The traditional Chinese method of making ink was to grind a mixture of hide glue, carbon black, lampblack, and bone black pigment with a mortar and pestle, then pour it into a ceramic dish where it could dry. In contrast to Chinese inks that were permanent, these inks could be washed away with water. Several studies observed that 14th-century Chinese inks are made from very small and uniform pine soot; the inks are superior in these aspects to modern soot inks. For the first process, more than one ounce (approx. 30 grams) lampblack of fine quality could be produced from a catty (approx. 0.5 kg) of oil. The Chinese had used India ink derived from pine soot prior to the 11th century AD, when the polymath official Shen Kuo (1031–1095) of the mid Song dynasty became troubled by deforestation (due to the demands of charcoal for the iron industry) and sought to make ink from a source other than pine soot. He believed that petroleum (which the Chinese called 'rock oil') was produced inexhaustibly within the earth and so decided to make an ink from the soot of burning petroleum, which the later pharmacologist Li Shizhen (1518–1593) wrote was as lustrous as lacquer and was superior to pine soot ink. A common ingredient in India ink, called carbon black, has been used by many ancient historical cultures. For example, the ancient Egyptians and Greeks both had their own recipes for "carbon black". One Greek recipe, from 40 to 90 AD, was written, documented and still exists today. The ink from China was often sought after in the rest of the world, including Europe, due to its quality. These qualities were described by Berthold Laufer: "It produces, first of all, a deep and true black; and second, it is permanent, unchangeable in color, and almost indestructible. Chinese written documents may be soaked in water for several weeks without washing out... In documents written as far back as the Han dynasty... the ink is as bright and well preserved as though it had been applied but yesterday. The same holds good of the productions of the printer's art. Books of the Yuan, Ming, and Ch'ing dynasties have come down to us with paper and type in a perfect state of composition." == Artistic uses ==

• India ink is used in many common artist pens, for example, "Pitt Artist" pens. • Many artists who use watercolor paint or other liquid mediums use waterproof India ink for their outlining because the ink does not bleed once it is dry. • Some other artists use both black and colored India ink as their choice medium in place of watercolors. The ink is diluted with water to create a wash, and typically done so in a ceramic bowl. The ink is layered like watercolors, but once dry, the ink is waterproof and cannot be blended. • Ink blotting is a form of art in which the artist places a blob of ink on special paper. Using a blower (a hair dryer will also work), the artist blows the ink around the page, then, if desired, will fold the paper in half to get a mirror-image ink blot on either side of the page, creating a symmetrical image. • Some artists who favor using monochromatic color palettes (one color but in different shades), especially grey tones, often use India ink for its ability to be mixed in water for lighter colors as well as its ability to layer colors without bleeding. • Tattoo artists use India ink as a black ink for tattoos. ==Non-art use==

'' stained with light India ink • In pathology laboratories, India ink is applied to surgically removed tissue specimens to maintain orientation and indicate tumor resection margins. The painted tissue is sprayed with acetic acid, which acts as a mordant, "fixing" the ink so it does not track. This ink is used because it survives tissue processing, during which tissue samples are bathed in alcohol and xylene and then embedded in paraffin wax. When viewed under the microscope, the ink at the tissue edge informs the pathologist of the surgical resection margin or other point of interest. • Microbiologists use India ink to stain a slide containing micro-organisms. The background is stained while the organisms remain clear. This is called a negative stain. India ink, along with other stains, can be used to determine if a cell has a gelatinous capsule. A common application of this procedure in the clinical microbiology laboratory is to confirm the morphology of the encapsulated yeast Cryptococcus spp. which cause cryptococcal meningitis. • In microscopy, India Ink is used to circle mounted specimens like diatoms or radiolarians for better finding them on the slide. • Medical researchers use India ink to visualize blood vessels when viewed under a microscope. • When assaying phagocytosis scientists often use India ink because it is easy to see and easy for cells to take up. • Scientists performing Western blotting may use India ink to visualize proteins separated by electrophoresis and transferred to a nitrocellulose or polyvinylidene fluoride (PVDF) membrane. • In ophthalmology, it was and still is used to some extent in corneal tattooing. • Once dry, its conductive properties make it useful for electrical connections on difficult substrates, such as glass. Although relatively low in conductivity, surfaces can be made suitable for electroplating, low-frequency shielding, or for creating large conductive geometries for high voltage apparatuses. A piece of paper impregnated with India ink serves as a grid leak resistor in some tube radio circuits. • In 2002, NASA patented a process for polishing aluminium mirror surfaces to optical quality, using India ink as the polishing medium. == See also ==