The mage can create an object that can store Essence.
Any object can serve as a Medicine Bag (it doesn’t even have to be a bag — it could be a rock or a knife), but those made from organic materials (leather, bone, plant fiber) are best. Plastics and metals impose a –1 dice penalty on the casting. The target number is one success per point of Essence the bag can hold, up to a maximum equal to the caster’s Gnosis + Spirit.
Note that the bag does not have any Essence points until some are placed in it. Any mage can use the Medicine Bag by casting the Sacramental Chain spell, below, using it to store Essence or take it out of the bag.
Guardians of the Veil Rote: Palm of Plenty
Guardians sometimes make these bags so that they always have some form of bribe to dispose of any troublesome spirits. Mysterium mages also employ this rote; it gives them a place to put some of the spoils from their explorations.
