Are you tired of the same old boring colors on all your t-shirts? Do you think glow-in the dark ink has just lost it shine? Well if you answered yes to either of these, or in my case both, thermochromic ink is the thing for you. Thermochromic ink is paint that changes color when it is heated. You can create a range of color changes like green to blue or brown to purple. You'll have the entire spectrum in the palm of your hand! And the best part is, you can use it on a variety of things including clothing, walls, even finger nail polish!