Barack Obama wasn't quite bullet-proof as he strode down Pennsylvania Avenue yesterday, but the new president was certainly "bullet-resistant," Slate explains. While the SWAT-team look might not be very presidential, several companies now manufacture lightweight protective clothing that can be worn under clothing or woven into shirts or coats.
The bullet-resistant gear features strands of materials like Kevlar—five times stronger than steel—woven into a netting and covered with plastic. No soft material can provide total security from bullets, but lab technicians test fabric extensively to make sure it can not only stop most bullets, but doesn't dent more than a few dozen millimeters.
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