In one form or another, gold has been used for decorative purposes for over 6,000 years. There is nothing quite like the appeal of gold, its glowing luster gives it a unique appeal that has transcended cultures for many centuries. Perhaps it is the fact that it is easily malleable and can be formed into practically any shape. Maybe it is that gold is highly corrosion resistant; safe from most acids and the weather, it is the perfect decoration when used in its purest form or as a plating. Gold plating that is used for decorative purposes should typically be at least 10 microns in thickness, however many items that are made for purely indoor use have been plated with layers as thin as one micron.
Many of these items are plated using electrolysis and gold salts that are usually based on either gold cyanide or gold sulfide. Used as an aqueous solution to plate items in the marine, aviation and architectural markets, this type of gold plating is becoming very popular, especially to plate stainless steel. Another method of plating is the use of rolled gold. This type of plating is used to create items such as luxury pens, cigarette lighters, some jewelry and other personal items. The process involves the use of a layer of copper or nickel alloy that is sandwiched between the base metal and the final layer of gold. Using both heat and pressure the gold is adhered using a milling process that makes it permanent. Once this process is complete, the gold is polished to a high luster that will last for many years. In 1831 the Royal Porcelain Factory in Meissen, Saxony developed the process for creating liquid gold.
The formula was kept a close secret until 1851 when it was finally patented. This liquid gold was a blend of powdered gold and various natural oils and chemicals. In 1879 the German precious metals group Degussa began to manufacture liquid gold then shared the recipe with British manufacturer Johnson Matthey. This was followed in 1905 with production in the U.S. by Engelhard Industries, a division of Hanova of liquid gold. Liquid gold is used to decorate many different glass and ceramic items such as expensive dinnerware or perfume bottles. It contains anywhere from 4 to 12 percent gold powder that has been dissolved in as many as 40 different oils and chemicals. The solution may also contain other metals that are included to help the solution flow more easily and achieve a much more uniform finish.