Extract from Otho Band's De Arte Quillomanteia:
... for all practitioners of the Art are acquainted with the ancient maxim: the quality of the bird makes the quality of the quill. By which quillwrights have long understood that certain birds yield superior quills, whilst others provide adequate quills and still others provide substandard quills.
The common goose and the swan, being considered superior, yet quillwrights do not restrict themselves to these birds alone. For they also make fine writing instruments from owl and raven and eagle and other feathers. And thus we consider now this underlying principle of quillomancy: how the qualities of the bird make the qualities of the quill.
First, let us examine the goose. The goose is a braw and bonny bird, a farflier and his meat is healthy. His wings are broad and sturdy and he flies in his formation like unto an arcking arrow or a spear in flight. Fast and high flies the goose and his wings must bear the tumult and tremor of many wingbeats ere he reach his distant destiny in north or south.
It is for this reason: his strength of heart and his hardiness of flight and the hardness of his feathers that the goose makes the finest and most durable quills.
...
Now let us consider one of the lesser known birds. In our lands, that bird that hight marshwadder is a very great bird indeed. He is girthsome and can not fly at all after his second year. And flies unwell before then! He spends his time standing in the wetwangs and marshes of the land. There he feeds upon the animacules that spawn in those damp and fetid waters. His wings are weak and he only flashes them once or twice in a season before laying, and thereafter rest tucked in and useless.
It is for this reason: that his feathers are therefore small and thin that they make for only the poorest sort of quill.