In the "Wakansansaizue" (a Japanese encyclopedia made in recent times), torinoko was described as 'being classified into three kinds of atsu-yo, chu-yo (medium torinoko paper), and usu-yo' and all ganpishi were called torinoko.
近世の『和漢三才図絵』には、鳥の子に関して「俗に言う、厚葉、中葉、薄葉三品有り」と記して、すべての雁皮紙を鳥の子と呼んでいる。