How did a gambeson add protection beneath a knight's mail armour?

A gambeson was a quilted garment made of leather or canvas that knights wore beneath their mail armour to provide essential defensive support.12

While mail was effective at preventing cuts, it offered incomplete protection against the force of impacts. The gambeson served two primary functions:
* Shock Absorption: Its stuffed and quilted construction acted as a cushion, helping to absorb and dissipate the shock of blows that would otherwise cause bruising or internal injury through the mail.312
* Layered Defense: By providing a padded buffer between the metal rings and the body, it enhanced the overall effectiveness of the knight's defensive equipment.1

In some instances, such as with the mail hood, additional padding was used to protect the head and neck, further demonstrating the importance of layered, padded undergarments in medieval combat. While knights used the gambeson as an underlayer, it was also used independently as a primary defensive garment by ordinary soldiers.312