Levels of Protection
There are three main types of soft body armor: ballistic, edged blade, and spike. Each is designed to provide maximum coverage to the vital organs and major blood vessels in the event of attack.
Ballistic armor is designed to absorb a bullet's energy on impact, slowing the bullet, and flattening it to stop penetration. Vests are
put through stringent tests by the National Institute of Justice (NIJ)
, and assigned a specific protection level based on the amount of ballistic protection they offer. In the current NIJ nomenclature, there are five levels of ballistic protection IIA, II, IIIA, III, and IV. Level IIIA is the highest standard for soft body armor. Levels III and IV, which can stop rifle fire, can currently only be achieved with the addition of hard armor plates.
Edged blade vests are thinner and more lightweight than ballistic vests. These feature a tight armor fiber weave in many layers that is designed to create friction against knives and other sharp objects and stop them tearing through.
Spike protection vests work in a similar manner to stab vests, but they have an even tighter armor weave, and the gaps between the fibers are narrow enough to trap pointed tips.