Embroidered cloth, hook-backed, standard flag size.
Following on from the East India Trading Company patch, and for much the same reasons of done-to-death pirate flags, here is the flag of the Vereenigde Oost Indische Compagnie, the VOC, or the United (Dutch) East India Company. Founded two years after the British East India Company, the VOC was similarly a tool of foreign policy for profit for the United Provinces.
This design is also fictional, but is actually pretty close to the real one. The monogram is centered and made larger against the back for easier reading, and doesn't have the chamber marking.
A fun little tidbit is that the VOC was the first company to ever have an Initial Public Offering, gathering funding from anyone with the money to do so instead of the traditional method of several nobles and wealthy merchants getting together to found a joint stock company.
Anyway, go do Goblin shit to get Tulips for Jan Company.