is said to have originated in the 15th century when a Japanese shogun broke a favorite tea bowl and sent it back to China to be fixed. But the repair job, which was done with metal staples (being the standard for repair at that time), detracted from the beauty of the bowl, so the shogun enlisted Japanese craftsmen to come up with a more aesthetically pleasing solution. Kintsugi
Although kintsugi repair makes it appear as though the original piece was mended with gold, the original process is essentially a form of lacquer art. Broken pieces are glued back together using urushi lacquer, derived from the sap of the Chinese lacquer tree. The final layer of urushi covered with fine gold powder. The toxic part comes from the urushiol oil which is found in very high amounts in the tree's sap, and which also happens to be the ingredient that's responsible for forming the dense and highly durable lacquer once dried. Fortunately, once the urushi dries and hardens the toxic effects of the urushiol oil are essentially nullified.