It's based on the Pascal -- a unit measuring force on a defined area, the equivalent of pounds per square inch (psi). In wasn't aware it was used to measure tensile strength, but upon reflection it makes sense. https://en.wikipedia.org/wiki/Ultimate_tensile_strength



+1. How much does it shrink? The stuff is everywhere. Contemplating the possible field uses now (cue sound of gears whirring and clanking in Babbage difference engine). Processing, processing ...