GEEK TEEZ Back to The Future Inspired Doc Brown's Flux Capacitor Women's T-Shirt High quality, preshrunk, super-soft cotton. Most colors are 100% cotton; Heather Grey is 90% cotton/10% polyester. Screen-printed in-house using water-based, environmentally-friendly inks. Vibrant, durable, and unique print featuring pop culture favorites, mashups, and parodies.