The Anonymous Conqueror was an unknown soldier with Cortez’s army, who later wrote a detailed account of the people, manners, architecture, warfare, armor and weapons of the Aztecs. He left some very valuable descriptions of the war gear of the Aztec and the surrounding nations. This description is from Chapter 4 of his account.
‘The armor which they use in war are certain loose garments like doublets made of quilted cotton, a finger and a half thick, and sometimes two fingers; they are very strong.’
A terse, but fairly detailed description.