Kugikakushi came into widespread use in the 16th and 17th centuries. They were used to provide a decorative metal covering for the joints of the huge beams and posts of shrines and temples and also in the grand castles that were constructed for various daimyo (feudal lords). Nail head covers were usually cast in metal from molds, and the surface was then finished in varying techniques. Some of the decorative methods include engraving the design on the mold, which creates an embossed pattern on the metal; openwork; chiseling or engraving on the finished object; plating; lacquering and enameling. Decorative motifs for many centuries played a prominent role in both the religious and daily lives of the Japanese people. Architecture was embellished with these symbols, which were representative of both the tangibles of nature and the intangibles of the spirit. Birds, bats, turtles, bamboo and family crests were some of the popular subjects for nail head covers. (See examples of kugikakushi on page 181 of “Japanese Antiques” by Patricia Salmon.)