We used the conventional degumming ratio to quantify how much sericin could be removed from the A. mylitta cocoons by each extraction method. The degumming ratios of the A. mylitta cocoons from each extraction method are presented in Table 2, and the SEM image of the A. mylitta cocoon before and after the extraction are shown in Fig. 1. Because we peeled off each of the cocoon layers before the SEM observation, some residual AmS in the upper layer (arrow) could be observed in the intact A. mylitta cocoon (Fig. 1A). Furthermore, the two brins of fibroins were not separated.