This is probably the best armor mod that you can get in the game. This mod increases the damage and energy resistance of most ordinary clothing (which can be worn under various armor pieces) and headgear. You have to join the Railroad and completing a Jackpot repeatable quest from PAM. After the quest, Tinker Tom will sell "Armored" versions common apparels though not as powerful as you can possibly craft (Up to Ballistic Weave V)