When we put our Iron, Diamond and Netherite Leggings on the Smithing Table and put an Ink Sac next to them, we add a pocket to them.
The properties of the pocketed armor are exactly the same as the originals. (Armor Values, Armor Toughness)
You can press P to access your pocket.
Iron Leggings Pocket Item Limit: 1
Diamond Leggings Pocket Item Limit: 2
Netherite Leggings Pocket Item Limit: 3