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Super simple heat activated invisible ink (not lemon juice)

Super simple heat activated invisible ink (not lemon juice)
5min $5 invisible ink utilizing the already-there heat sensitive chemical on thermal paper. I think this works much better than lemon juice because lemon requires you to half burn the paper to show up.this requires much less heat.
 
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Step 1Get the stuff you need (not much)

Get the stuff you need (not much)
you need,

1.thermal paper

2.water and a cup

3.tooth picks/q-tips (to write with)

4.candle or other heat source

NOTE: If you dont have blank thermal paper just use receips from stores and gas stations (use only the paper that is shiny on the one side with dark shiny black writing). Be sure to use the part that is blank and not the printed on part.
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26 comments
Mar 8, 2012. 3:44 PMnomooremr.niceguy says:
Does this ink remain visible? or does it disappear when it cools down again? Thanks for your input.
Aug 30, 2010. 4:05 PMinvitediva says:
i became a pro member thinking there was step after step 4 --- i have done everything and have been able to get the liquid to look milky but when i use a q tip to apply it to paper and heat the paper, nothing happens. any thoughts.
Aug 12, 2010. 12:16 AMnutsandbolts_64 says:
waaaaaait........ you mean I could use old receipt paper for that? as in the modern receipt paper? the smooth-feeling paper? if so, I'm buying a roll! lol
Jan 11, 2007. 12:16 PMstone3408 says:
While we are on the topic of thermal paper. There is a chemical out there that will react with thermal paper and turn it black. It is sort of a yellow color. Any thought on what that maybe.
Nov 10, 2007. 12:02 PMX_D_3_M_1 says:
iodine?
Nov 18, 2007. 10:46 AMstone3408 says:
That works but, I'm looking to use it in fingerprinting application and iodine to too hazardous.
Jun 9, 2010. 6:46 AMscratchr says:
You should worry more about what is in the paper. (hint:Bisphenol A)
Nov 18, 2007. 7:48 PMX_D_3_M_1 says:
o. u could do corn starch and iodine, starch turns purple/black, if u didnt mind danger
May 20, 2007. 5:43 PMFenwick says:
I know Alcohol turns thermal paper black sometimes. It's not very consistent though.
Sep 30, 2007. 7:37 PMinstructa-fan says:
correct me if i'm wrong, but what this is, is soaking thermal paper in water which gets some funky chems in the water and this will be your thermal activated ink??? or do you write on a reciept???? i'm confused...0\ _ /0...grr...
Mar 29, 2010. 12:52 PMlasermaster3531 says:
the chems in the water is the ink.

Mar 2, 2007. 6:07 PMthejrb says:
You spell it Receipts.
Jan 4, 2008. 12:47 PMtechnodude92 says:
I before E except after C...
Jan 2, 2008. 7:58 PMkillerjackalope says:
Great source of thermal paper is fax machine paper for old school ones, you can still buy it at most places like staples and it's pretty cheap for a large ream...
Feb 28, 2007. 7:11 PMusuck says:
for the ink
Feb 28, 2007. 7:10 PMusuck says:
can u use regular paper?
Feb 25, 2007. 2:58 PMplayingwithfire22 says:
it looks exactly like yours throughout the steps. Mine may be to watery so ill try less water to more paper. Also you use this on regular paper and not the thermal paper right?
Feb 24, 2007. 11:48 PMplayingwithfire22 says:
Sorry to bother, but I am having trouble with this. I follow all of the steps. I put thermal paper in the water and wring it till it turns whitish. I then apply some to a piece of paper and wait for it to dry. I then hold a lighter to it and nothing happens except maybe a brown mark from me burning the paper. Any thoughts on what i could be doing wrong?
Jan 17, 2007. 6:14 PMfoney_email says:
I hear Urine works as invisible ink. I have never tried it though.
Jan 12, 2007. 8:04 PMVertigo666 says:
just wonering, where would you buy thermal paper?
Jan 9, 2007. 11:45 PMjgodsey says:
I'm lazy I prefer Noodler's Blue Ghost invisible Ink but this is a handy backup!
Jan 9, 2007. 10:00 PMIlluminatedAntichrist says:
Cool, i'll try it.
Jan 9, 2007. 9:46 PMdcshoeco33 says:
thats really cool

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