Indelible mark of democracy: The story of India’s election ink

Our eighteenth general election is almost here, with 97 crore eligible voters helming the world’s largest democratic exercise. It is a matter of prodigious pride and, in parallel, a colossal logistical nightmare. Every possible news angle will be explored by ink slingers and reporters. Who will win? By how much? Or who will lose? Will there be pre-poll chicanery? Or post-poll violence? The TV channels are already in thrall, but have most voters turned a deaf ear to the abundance of noise, having made up their minds already?

This essay has nothing to do with politics, as I am only a rational scientist, but rather with the chemical stain on our elections—that purplish-black smudge of victory that every voter brandishes on his finger, flushed with the euphoria of polling. We are inked, quite simply, to prevent voter fraud and the dodgy elector from voting twice. As symbolic and romantic as the stamp of the Scarlet Pimpernel, the distinctive purple daub darkens quickly into black and doesn’t disappear for weeks on end. Staying power is, after all, the hallmark of statecraft.

Voters’ ink hasn’t really been around for all that long. It might have been developed by a Colombian chemist, José Vicente Azcuénaga Chacón, and used in a local election there in 1957. The Indian connection is older, and a patent for the ink was filed in 1950 by the National Research and Development Corporation (NRDC). The first ink was developed by the National Physical Laboratory (NPL), a constituent of the Council of Scientific and Industrial Research (CSIR), which licenced the production to a small company in Mysore called Mysore Paints and Varnish Limited (MPVL).

MPVL was originally called Mysore Lac and Paint Works Limited and was founded, like most good things in the erstwhile Mysore State, by the philosopher-king Maharaja Krishnaraja Wadiyar IV in 1937, in yet another shining example of the outstanding contributions of this single individual to the continuing progress of this country, right down to the present day. The ink was first used in India in 1962 in our third general election, but only in the Mysore of yore.

MPVL is still the sole supplier of the indelible ink that is used to mark the voter. It is now government-owned, with a monopoly on the product. It sells the product only to the government. It exports the ink to more than 25 countries, and the product also fulfils any local specifications. The Election Commission places its order, considering the size of our electorate, much before the elections are notified. The country needs 30 lakh vials of the marker for the upcoming elections, and this will cost the exchequer INR 55 crore. A 5-millilitre vial is good for 300 applications. However, other questions arise. What were we doing in our earlier elections? What were other countries doing? How many countries have used or still use electoral ink?

The chemistry beneath electoral ink is fascinating. Its key compound is a substance called silver nitrate, of which a 12–18 per cent solution in water is used along with a purple dye colourant and a biocide to prevent skin infections amongst voters, as the same marker rod is used for everyone and dipped into the bottle between applications. Apparently, there is a fourth ‘secret’ ingredient, but this is hard to prove or disprove. When the ink touches the natural salt on human skin and nails, silver nitrate changes to silver chloride, altering colour in the process and lodging within the protein of the finger, cuticle and nail.

To understand how purple turns black, we need to know a little solid-state chemistry. Silver chloride is what chemists call a salt because it is made up of positively and negatively charged species we call ions. To form silver chloride, a neutral silver atom loses a negative electron and forms a positive silver ion. Simultaneously, a neutral chlorine atom picks up the electron and forms a negative chloride ion. Positive ions are much smaller than negative ones. In our case, comparing the sizes of the positive silver and the negative chloride ions is like comparing a marble with a football. Knowing this, it is easy to figure out how silver chloride looks like from the inside.

Imagine you have some footballs and marbles and have to pack them together tightly in a big box. You would start by arranging the footballs so that they touch each other. After that, it would not be difficult to let the marbles slide into the little spaces between the footballs. Voila, this is exactly what the solid-state structure of silver chloride looks like. The important point is that the silver ion is so much smaller than the chloride ion that it starts slithering into the gaps formed by the chlorides.

The silver ions start colliding with each other, and for reasons not quite known, they form a small clump of silver. At this stage, light enters the picture (the voter is presumably not in a dark room) and conveys electrons back from the negative chlorides to the positive silvers until effectively they become neutral silvers again, in other words, silver metal, which is black in colour, not silvery white as we know it, simply because the clusters are so small. Every voter is therefore paid a few million atoms of silver for his efforts when leaving the polling booth. The price to pay in return awaits each one of us!

This whole sequence of events takes place within minutes, and there you have your black mark. Amazingly, a man called George Eastman discovered this process 125 years ago and used it to create the first photographic film in a company he founded, the Eastman Kodak Company, in the US. The black component of a black-and-white negative or print is exactly the same black colloidal silver on your fingernail that is formed after the indelible ink has been applied to it.

Legends surrounding indelible ink are legion. The armed guerrilla Shining Path of Peru constantly threatens to kill those found with ink stains to dissuade others from voting. During the 2008 Zimbabwean presidential election , some people without the stain on their forefinger were attacked and beaten by government-sponsored mobs. In the 2010 Afghan parliamentary election , the Taliban threatened to cut off the tattooed digits of voters. During the 2013 Malaysian general election , voters reported that the ink washed off under running water. As a student, I remember the rumours in Bombay in the 1971 elections that the smudge could be removed with the juice of an onion and that Indira Gandhi had procured a secret formula for disappearing ink from the Russians. The conspiracy theories don’t change, only the embellishments do.

Around 30 countries use indelible ink for elections, and all of them are what one might term the “third world”. India is an outlier in this group of small, relatively poor countries. Why do more advanced countries not feel the need for this application? Clearly, cost and logistics are not issues in first-world countries. Cultural and legal issues, especially those concerned with individual privacy, might be, but mostly I suspect that there are numerous technological advances such as biometric identification and electronic voting that might render electoral ink unnecessary. As for earlier times, even in India before 1962, I would conjecture that voter fraud was not considered a major problem, and anyway, elections of the modern type are barely 100 years old.

An analogy with locks and keys is illustrative. Locks first gave way to plastic cards that were inserted into doors to open them, which then changed to cards that were swiped to unlock doors, until now we have biometric entry across barriers. I strongly suspect that our government has already acquired this last technical capability for voter identification and, hence, the ability to prevent voter fraud without the use of the purple tattoo.

In this forthcoming election, the Election Commission has notified that voters over 85 may vote from home, and those above 80 with medical problems may also choose to do so. I am sure some kind of electronic validation will be in place for such voters, and we are hardly likely to see armies of people scurrying around with little bottles of voter ink in search of these old and sick people. It’s just a matter of time before the use of the purple liquid is relegated to our electoral past. The indelible ink will be rendered invisible. Unless there are further demonetisations of our currency and we are inked in the banks after exchanging notes, a lot of lovely chemistry along the way is all set to go to waste, with copious ink having been spilled for nothing! But that’s the way it is.

The author is an Emeritus Professor in the Indian Institute of Science, Bengaluru and is the author of Bharat: India 2.0 published in 2021. He has an H-index of 104. Views expressed in the above piece are personal and solely that of the author. They do not necessarily reflect Firstpost’s views.