Spectra is one of the brand names for the ultra-high-molecular-weight polyethylene (UHMWPE, UHMW) https://en.wikipedia.org/wiki/Ultra-high-molecular-weight_poly

Spectra is one of the brand names for the ultra-high-molecular-weight polyethylene (UHMWPE, UHMW) https://en.wikipedia.org/wiki/Ultra-high-molecular-weight_polyethylene https://en.wikipedia.org/wiki/Ultra-high-molecular-weight_po... I mentioned in one of my other postings in this subthread. I've gotten the impression, at least from one vendor, that mixed aramid and UHMWPE fabrics are common for law enforcement vests, due to their lower cost. And of course plain aramid is still cheaper, so is still used a lot.