Election ink

Electoral ink, indelible ink, electoral stain or phosphoric ink is a semi-permanent ink or dye that is applied to the forefinger (usually) of voters during elections in order to prevent electoral fraud such as double voting. It is an effective method for countries where identification documents for citizens are not always standardised or institutionalised.

During the first election in India, the election commission faced one of their biggest issues: identification theft. To protect people from casting their vote twice they reached out to the NPL (National Physical laboratory) of India. A team of scientists led by Dr. M.L. Goel FCS (Fallow's Chemical Society, London) to make an ink to protect the interest of Indian population. The Indian government started the use of Indelible ink during the third election and since then has used the same products till today. The Indian government also exports ink to many developing countries for their elections. The most common election ink used worldwide was invented by Filiberto Vázquez Davila, a Mexican biochemical engineer.

Electoral stain is used as an effective security feature to prevent double voting in elections. Ink is normally applied to the left hand index finger, especially to the cuticle where it is almost impossible to remove quickly. Ink may be applied in a variety of ways, depending on circumstance and preference. The most common methods are via dipping bottles with sponge inserts, bottles with a brush applicators, spray bottles, and marker pens. With all methods the finger should be left to dry for 15–30 seconds and exposed to light before being cleaned to ensure the mark remains visible for the desired length of time.

Electoral stain typically contains a pigment for instant recognition, a silver nitrate which stains the skin on exposure to ultraviolet light, leaving a mark that is impossible to wash off and is only removed as external skin cells are replaced. Industry standard electoral inks contain 10%, 14% or 18% silver nitrate solution, depending on the length of time the mark is required to be visible. Although normally water-based, electoral stains occasionally contain a solvent such as alcohol to allow for faster drying, especially when used with dipping bottles, which may also contain a biocide to ensure bacteria aren't transferred from voter to voter.

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