Mizushima Silk Industries has produced a fibroin protein solution by using silk dissolved in calcium chloride and ethanol. The fiber combines the properties of silk and synthetics. The fibroin fiber has low adhesion, and it cannot be bonded to the carrier fiber without additional processing. To improve adhesion, 1 liter of acrylic resin solution of about 30 percent by volume concentration can be added to the solution containing 1 kilogram of egg white and 3 liters of water. The fibroin protein solution is then adsorbed by the carrier, and dried. The thread is immersed in an ethanol solution of 70-80 percent concentration at 60-70 degrees Centigrade for 20-30 minutes. This ensures that the acrylic resin, along with the egg white, are adsorbed by the synthetic or vegetable fiber. When dried, the acrylic resin becomes insoluble. The fibroin protein bonded with the egg white becomes insoluble as a result of the ethanol treatment, thus ensuring that the fibroin can be bonded to the carrier strand.