"Color-changing leather" is a kind of high-grade leather made by special technology. According to the exquisiteness of the designed patterns or characters, it is necessary to make a "copper electric engraving" or "corroded zinc engraving" first. When the board is heated by special equipment, the discolored leather will discolor where it contacts the board. Color-changing dermatoglyphics are noble and dignified, suitable for the covers of high-end hardcover books, high-end gourmet dishes and high-end.