Japanese Mirrors

Mirrors are usually considered primarily as implements for personal grooming but, in Japan, mirrors were used for far more than reflecting one's image. Within Japanese culture, mirrors are one of the most potent symbols of power, revered as sacred objects representing the gods. Mirrors are also admired as artistic objects, as they have intricate pictorial designs on their backs.  The technology needed to cast metal mirrors was introduced to Japan from China around the Yayoi period (ca. 3rd century BCE–3rd century CE). During the Heian period (794–1185), the mirror was included as part of the elaborate toiletry sets used by aristocrats. Though the earliest mirrors were fashioned after Chinese mirrors, in time mirror makers began to depict Japanese style designs and motifs from the Japanese natural world. In ancient times, round mirrors typically had a knob in the center of the back, through which a cord would be strung. Later, as the hand mirror (a round mirror with a rectangular protruding handle) came into use, designs became more pictorial, covering the entire back. These mirrors with designs on the back became popular among commoners in the Edo period, and the motifs used in these designs became diversified.

The designs on the back of mirrors tend to include motifs of things found in nature (plants, flowers, birds and butterflies), landscapes, or auspicious motifs like the crane. Intricate and detailed designs are avoided, as the basic shapes must be formed using sand. The loam molds that are used to cast mirrors are particularly suited to designs in high relief. 

The mold is moved to the foundry for casting. The casting alloy (a mixture of copper and tin are used to make bronze) is melted and poured into the mold. 

The mirror comes out of the mold with unnecessary parts such as the sprue (the protrusion where the metal was poured into the mold) still attached. These parts, the edge, and the surface of the mirror are sanded down and polished. 

A final step is to smooth and buff the mirror's surface with charcoal. The preferred charcoal for this task comes from the bigleaf magnolia or tung wood. In this way, the surface of the mirror is finished step by step to eliminate marks and unevenness. In the past there exited a process known as hontogi whereby the metalsmith would rub mercury onto the mirror. Today, the surface is rubbed instead with nickel or a nickel amalgam.

Finally, let us take a look at some little known but amazing Japanese mirrors. When sunlight hits the mirror shown here, it reflects a hidden image onto the nearby wall. In Japan there exist mirrors that can reflect characters or pictures onto walls even though no such design is visibly evident on the mirror's reflecting surface. These are known as makyō (magic mirrors).

Makyō mirrors were first produced during the Edo period (1615–1868). Although production ceased for a time, it was revived around 1974 by Yamamoto Ōryū, who was designated as a Living National Treasure (officially, a Holder of Important Intangible Cultural Property). In June 2014 Prime Minister Abe Shinzō made headlines  during his visit to Italy by presenting a magic mirror with hidden Christian imagery to Pope Francis.