Goldenrod Color-Changing Paper – Halloween Science
Order now at http://www.stevespanglerscience.com/product/1239 This paper turns bright red when dipped in bases such as ammonia and washing soda, and turns back to its normal color when you dip it in acids such as vinegar or lemon juice.
u freaked me out steve! and then u said that its not blood, and i was like "PHEW! thank God"
i want to line my house with that then spray it before people come over