Oak Galls as source of ink (e.g. for printing recipe)

Since game has introduced new common tree of oak, why not mix it together with other existing production line, printing?
Oaks are known to bear abnormal growth lumps also known as oak apples. They were widely used to make ink: https://en.wikipedia.org/wiki/Iron_gall_ink
So idea is around that: gatherer picks galls from oaks, then ink maker produces ink from galls and minor amount of scrap metal