stolen supplies dropped by corsairs usually salvages for glass vial or ink for me
you should farm something else, and buy the ink IMO - thats the fastest to "farm" it
Just buy the ink. Or a cheaper method: farm dust and plant fiber. use the dust to craft tempered glass vial. Then use the plant fiber and tempered glass vials to craft ink. All the crafting can be done in Seitung Harbor.
feather farming outside of seitung harbor is a good way to get money, plus there are several yeti along the way that drop the stolen supplies that can salvage into vials.