The official Tau Day shirt. I wanted to wear this on my birthday (because my birthday falls on Tau Day), but it was through a Kickstarter, and the Kickstarter didn't end until July 7th. It came today.

It has a bunch of digits of Tau (just like the pi and phi shirts... did I upload pictures of that)

There's a caption at the very top line that says:
"τism is based on reason, not faith: τists are never πous."
(Taoism is based on reason, not faith: Taoists are never pious).

On the back is part of the Unit Circle, but with Tau.

I think I officially have more math shirts than Portal shirts.
I think I have 9 Portal shirts, including the one I made. I now have 6 math shirts that I bought, plus the three I silk-screened, plus the one I heat-transferred, plus the at least one I hand-painted.

Now all I need is an Euler's Number shirt, and I'm content with the number-shirts. I have one of tau, pi, phi... just need Euler's number,and I got all the nice numbers :D So tau, pi, phi, NDC insult, i<3u, The Furry Fractalist x3, Mandelbrot shirt, and my GoL shirt for the math stuffs... at least. I might have more. xD