Instructables

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.
 
Remove these adsRemove these ads by Signing Up

Step 1: 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.

Step 2: Add paper

fully soak in water

Step 4: Finish

keep wetting and wringing out the paper untill your ink looks like whats in the pic below. the more concentrated your ink the better it will work.
Pro

Get More Out of Instructables

Already have an Account?

close

PDF Downloads
As a Pro member, you will gain access to download any Instructable in the PDF format. You also have the ability to customize your PDF download.

Upgrade to Pro today!