Armor plating is by definition to install armor, typically on a vehicle.
There are many differnt types of armor including plates made out of titanium, ceramic, kevlar and other ballistic resistant material. General Name, Symbol, Number Titanium, Ti, 22 Chemical series transition metals Group, Period, Block 4, 4, d Density, Hardness 4507 kg/m3, 6 Appearance Silvery metallic Atomic properties Atomic weight 47. ... The word ceramic is derived from Greek, and in its strictest sense refers to clay in all its forms. ... Chemical structure of Kevlar. ...
Platearmor was a much more complicated type of armor because it was not as flexible as chain mail.
The style of helmet that was worn with full platearmor in its full glory was the armet and bevor, which covered the entire head, neck and face while still allowing the wearer to turn his head.
Plate gauntlets, unlike the chain mail ones, were very complex works of metalworking that covered the hands with iron plates while allowing free movement of the fingers.
Full battle armors impose the QUI penalties associated with their base armor, PER and AGI penalties for their corresponding helms and gauntlets, and the associated QUI penalty resulting from the corresponding boots, if any.
Variations on full battle platearmor (such as cavalry plate) are made for specific types of combat and mobility needs, providing various levels of protection and QUI penalties.
Armor can be repaired before it has lost all of its armor points, of course.