An arrow bag is a modern term used to describe the container used to transport and distribute medieval arrows during a battle. Very commonly depicted in 15th century manuscripts if a container for arrows is to appear. Depictions vary from a soft textile bag with a soft body to a container which appears to be made of wicker with a white textile covering. In both cases, the covering is likely to be of linen, possibly waxed.
The soft bodied version appears to have a drawstring opening at the nock end of the arrow, and sometimes the base. Their appears to be a leather spacer for the holding the arrows apart to preserve the fletching. This is also supported by the 16th century Mary Rose find where such spacers have been found in situ. They appear to hold approximately two dozen arrows. In transport, these type may have been contained in barrels.
On the battlefield, such arrow bags may be been relayed to the ground near archers from the supply train or a closer store where needed. Archers then appear to have collected their arrows and tucked them under their belts until they were ready to be shot.