"the essence bag can be crafted to allow additional storage when adventuring. Also see: essence refiner."
To craft the essence bag you require a crafting bench and to place the listed item in the order shown;
Place leather in the top left, top, top right, bottom left, bottom and bottom left slots, then place any coloured wool on the left and the right sides with a golden nugget in the center.
The bag of holding only has 12 slots of inventory space, every essence including pure essence, high essence core and the base essence core.
When arcane essence is placed in the bag, it duplicates whatever item was in the slot before being replace with the arcane essence otherwise it dupes to nothing. If a stack of arcane essence is placed in a glitched slot, it will replace the stack with a stack of whatever item it is duplicating, Arcane essence can't be duplicated.