Done yet?

Cook the lobster by touch. The heat from your finger will turn the green thermochromic ink clear, revealing the red of the cooked lobster printed beneath. This ink was formulated to change color at approximately 88˚ degrees Fahrenheit, but can be modified for warmer or cooler temperatures.

This simulation is meant to replicate the printed example in Ed 9.

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Ed #9 Understanding Ink

Image Credit: Jeff Sciortino