Introduction: How to Make Invisible Ink
So I came upon this amazing formula for making an invisible ink , with could only be seen under UV/Black light.
How?
Glad you asked!
Black lights are not that different from any other type of light, whether incandescent, fluorescent, or just the age old candle flame. The difference is that black lights emit most of their light waves just outside the range humans can perceive, in the Ultraviolet (UV) part of the spectrum. When a UV light wave hits an object containing substances known as phosphors, those phosphors will naturally fluoresce, and glow.
Phosphors are present in many daily use objects like Vaseline, tooth whiteners, body fluid (you know, the gross ones...), bank notes, laundry detergent etc.
So, when you know, let's start.
Step 1: Stuff Needed
Get :
A Highlighter (Any, really, absolutely any)
Pliers
Hot Water
Empty Cup
A UV/ black light
A Water tight Jar.
Step 2: Take It Out
Depending on what kind of highlighter you have you can usually open them up with pliers. Don't destroy the highlighter trying to get it open. Once you get it open take out the tube of ink that is inside, and pull the tip (the part you write with) out of it with pliers.
Step 3: Microwave
Put the tube and tip into a cup of water. Put it in the microwave until it starts boiling.
Step 4: Into the Water!
Take out the tube with the pliers and squeeze all of the ink out into the cup. Do the same thing with the tip.
Step 5: Fin!
Add enough water so that you can see through the water clearly but it is still dark. Put the tube and tip back into the cup and put it in the microwave until it boils again.
Step 6:
Put the parts back into the highlighter and you have your invisible pen! Dip the pen into the ink and write with it! To save the ink put it in a water tight jar so you can refill your pen. Your ink will show up under a UV light or black light.
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Participated in the
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2 People Made This Project!
- casEy lyNnm made it!
- bob370492 made it!
29 Comments
Question 6 months ago on Step 6
How do you wash it off your skin?
1 year ago on Step 6
This doesn’t work. To be invisible it has to be diluted to the point where it no longer shows up under a uv light.
Reply 11 months ago
not sure what the point would be in having an invisible ink that cannot be made visible when needed.
Question 2 years ago on Step 6
would this work for tattoo ink?
2 years ago on Step 3
Boiling Water in a microwave can be very dangerous. Under the right conditions opening the door can cause an explosion of steam into your face and body.
3 years ago
Man thnx for the tip it worked for me illl post a pic on my insta @damarbro909
7 years ago on Introduction
I'm guessing it was diluted so that it would appear invisible. Visible highlighters would show under a black light (guessing) but wouldn't be invisible. Did you try it with the dollar store highlighters?
Reply 4 years ago
Check out my comment, it was easy AND invisible!!
4 years ago on Step 5
Thankyou!
Worked great on my first attempt!
For those asking, when it’s thinned down enough it looks very coloured in my jar and a bit when I paint it on. When it dries it leaves just the faintest of colour tint on very pale skin but at the right mix, you can have it invisible but still quite bright under the black light!
Also I don’t have a microwave, I just boiled water and poured that over the pen insides and allowed it to sit. Once it had cooled I then squeezed the tubes from the pens to get all the ink colour out.
I then used a paintbrush because I couldn’t quite get all the colour out of the pen nib.(it still looked like regular highlighter) when I used a paintbrush it was totally invisible!!
5 years ago
how much water do you use?
5 years ago
Nope, didnt work for me either. Tried different brands and colours of highlighters. By the time the stuff is dilute enough not to be seen in day light, it doesnt show up under UV either. If its strong enough to show up under UV, it can be seen in daylight....It could possibly be that the UV im using is in the 390 - 405 nm band. It may work with shorter wave UV......
However, whilst doing the experimenting, i've found something in the kitchen that glows wonderfully, well, I found many things actually, but trying to narrow it down to something that wont go/isn't rancid, and is water soluble and kiddie safe. Once dried, my coffee seems to glow a nice sickly green yellow, probably the milk and sugar...but dont fancy the likely smell of the pen/ink after a day or so....
6 years ago
How long does it last?
Reply 5 years ago
Hello
Reply 6 years ago
As Long as Its Contained
6 years ago
Is this toxic or unsafe by any means (excluding eating it, of course)? because I don't want to put something on my skin and then it ends up burning and giving me a rash.
Reply 6 years ago
Its Fine I Have it All Over My Hand
6 years ago
It is a cool idea and I am going to get mine out right now and try it ,I like this idea and I made it
6 years ago
I didnt work.
No matter how I try.
I really need help.
6 years ago
Worked great - thank you!
7 years ago on Introduction
Just to be clear, if I go down to Walmart and buy a Halloween black light-bulb, would that work? I've tried another set of "Halloween black lights" and they didn't seem to make the ink show up. Thanks!