That blue mark, boys and girls, comes from the indelible ink, or some prefer calling it election ink. Once you have this mark on your finger, it means that you're now officially an adult.

What is indelible ink, you ask? Here's the who, what, where and how:

Which smart fella came up with the idea?

The idea first came about in the year 1951/1952, the year of India's first ever General Elections. At the time, the country's election commission was having a tough time dealing with identity theft, as they soon discovered that there were duplicate or fake votes. The commission reached out to the National Physical Laboratory of India to find a solution to the problem.

A team of scientists led by Dr. M.L. Goel went to work and they later developed the indelible ink. The ink was first used during India's third General Elections in 1962. Indelible ink has been used in every General Election since.

In 1994, a Mexican biochemical engineer named Filiberto Vázquez Davila developed an enhanced version of the indelible ink that's currently being used all around the world.

OK, but what do they use to make indelible ink?

Definitely not the same ingredients as your usual nail polish, of course.

Indelible ink is made of a chemical compound called silver nitrate. When applied to the skin and exposed to ultraviolet light, it leaves a mark that is almost impossible to wash off.

The stain is so strong, in fact, it is only removed when the external skin cells are replaced.

That is why silver nitrate is also used in medicine. The chemical is typically used for pain relief and to remove stubborn, unwanted tissue from a non-healing or infected wound.

A bottle of indelible ink usually contains either 10 per cent, 14 per cent or 18 per cent silver nitrate solution - depending on how long you want the stain to last.

So, it's a very good reason not to do this after you've voted:

Gasp! Will the ink ever go away?

Well, if applied on the skin, the ink will usually last between three to four days. When applied to the fingernail or the cuticle, the ink will last up to four weeks. That's the reason why the election commission paints your entire index finger.

ALSO READ: Your Questions About Postal Voting Answered Here

Before you complain about having an annoying stain on your finger for weeks on end, the indelible ink used in India only disappears with the growth of a new nail if it's applied on the cuticle, which is about four months. Glad we're not in India now, huh?

So, when did we decide to use it in Malaysia?

Actually, not very long ago. Indelible ink was first introduced in Malaysia during the 2013 General Elections. Initially, indelible ink was supposed to be used in the 2008 Elections, but three days before polling day, the election commission decided against using it because the Attorney-General doubted its legality.

As expected, there were some drama regarding the use of the ink in Malaysia. A lot of voters claimed that they were able to wash off the ink using just water, vinegar or hand sanitiser, despite the election commission stating otherwise.

The bad press got so, uhh, bad, the election commission was forced to come out and publicly demonstrate that the ink could not be scrubbed off by whatever means necessary.

The blame eventually fell on the shoulders of polling officers, who were accused of not shaking the bottle properly before applying the link. Tough luck, guys!

Why do we continue using it then?

Well, other than preventing duplicate votes or identity theft cases by not letting those already marked with the ink cast their votes again, using indelible ink would in some way ensure that the election process is fair and just.

It is also currently the most effective way to prevent double voting, so unless there's a better alternative, indelible ink is still the way to go.

The government has been mulling the use of a biometric system to replace indelible ink, but considering that they have been mulling the decision for five years, we guess it won't be coming anytime soon.

Oh, here's a bonus: according to this report by The New Straits Times, GE14 voters will get a "finger massage" at polling stations. Umm, what?