Neither gold powder nor gold foil can be swept up with a pen, because no matter how thin the brush is, it will leave traces. The correct way is to gently wipe the surface with mercerized cotton dipped in gold powder, wipe it again after half an hour, repeat it several times and wipe it again the next day.

When the ash is dry, it can be polished. Polishing requires meticulous patience. According to the mesh number of sandpaper, slowly polish it from low to high. Don't rush, or you will hurt the utensils. This process is time-consuming. At the end of grinding, it should be smooth, and the joints should be closely combined without gaps. Then apply black paint, not too thick, or it will wrinkle, evenly apply a layer, dry in the shade and polish, clean and polish again, and repeat several times until the surface is smooth.

In fact, most of the metal materials we meet in our daily life are not pure metals, but their alloys. Alloy refers to a mixture with metallic characteristics formed by heating and melting some other metals or nonmetals in metals.

For example, steel is composed of iron, carbon and a small amount of other metals in a certain proportion, rather than pure iron. White copper is an alloy of copper and nickel, which can be used to make coins. The usual 18K gold refers to an alloy with a gold content of 75% and a certain amount of silver and copper.