It used a technique called byakudan nuri (lacquered sandalwood) where lacquer is painted on top of gold foil, and it is strong and practical since saikin does not come in direct contact with hands.
金箔の上に漆を塗る白檀塗りという技法を利用したもので、截金が直接手に触れることがないため堅牢性が高く実用的である