I prided myself in taking a styrofoam cup for a while. But it took so much energy to keep from crushing it that I broke down, went to Walmart, and bought a 12 fl oz plastic kids cup that is very sturdy. So I increased my pack weight up from 0.03oz to 0.7oz. Peace of mind came knowing I can smash my pack w/o worrying about my mug--- all for the price of 0.67oz.

-Barry