Once armored vests, or
"flak-jackets," were introduced to UN
forces in early 1952, they became the most
important piece of equipment an infantryman had,
next to his weapons.
"Flak" derives from a
German Antiaircraft gun,
"Flugabwehrkanone". The Marine vest was
sleeveless, had nylon padding around the upper
chest and shoulders, and plates of Fiberglass
bonded with resin that covered the lower chest,
back, and abdomen. The Army vest used layers of
basket-weave nylon.
Neither vest could stop a rifle
bullet at close range, but both could reduce
casualties by mortar and artillery fire and hand
grenade fragments. In addition, the pistol
ammunition used by CCF burp guns could also
frequently be stopped. An Army report concluded
that the vests reduced chest, back, and abdomen
wounds by up to 70 percent.