Nicholas writes: “I found your tattoo emporium a while ago and found it so fascinating I wanted one for myself. I wanted to get a UV tattoo for the ability to conceal and the added effect with the black light, of course. I find Euler’s formula to be one of the most magnificent discoveries in mathematics and I wanted to use it in my tattoo. I came up with e^(i pi/2) because its just i. I thought it a great idea then to get an invisible tattoo as the number i.”