The items you receive through the journey go into the bag or the inventory.
The inventory stores a limited number of items to be carried by a character at all times.
As a character advanced in-game, more and more items are obtained and placed in the inventory. Quest items take over the slots temporarily while the most of other items are usually kept longer than one or two quests and the bag becomes crowded.
Characters give up owning certain items to make space in the default bag. They can sell or trade to a Merchant NPC or to a fellow player. However, selling and trading requires travelling to the village or time for another player to respond to the offer advertised via chat window. Extra bags can be extremely useful and appreciated.
A number of choices are given when purchasing an additional bag from a Supply Merchant NPC located in starting villages and capital castles of each nation. Bags are also acquirable via loot drops during the hunt.
Drag-and-drop the bag item to the Character window
After purchasing a bag, you can double-click the item to equip or open the Character window via shortcut key “C” and drag-and-drop the bag from the inventory to the one of the bag slots occupying the left side of the Character window.
With the additional bag(s) on equip, pressing “I” key will open the same number of inventory windows as the number of equipped bags. In order to disable a bag, simply double-click on the bag from the Character information window or drag-and-drop the selected bag into the default inventory.