This Attack of the 50ft Woman t-shirt is officially licensed and manufactured by Hi Fidelity Entertainment. The front is screen printed on a yellow t-shirt made from 100% cotton.  No design is on the back.

Size,          Brand,        Armpit to Armpit, Top to Bottom
Medium     Gildan                   19.5"                29.5"
Large        Gildan                    21"                   30" 
X-Large     Gildan                   23"                   31"