As pens became items of luxury and status rather than mere utilitarian tools, gold was embraced by pen manufacturers such as Montblanc, Cross, and Parker looking for ways to show off their latest fountain pens and other writing instruments. Pure gold is too soft to stand up to the daily use of an avid letter writer or journalist, so gold is mixed with alloys to make it more durable. These alloys also give the gold different hues. For example, the recipe for yellow gold calls for 75 percent pure gold mixed with equal parts silver and copper. A redder gold can be achieved by upping the proportion of copper, while a white gold can be produced by substituting the silver and copper blend for either nickel or palladium.
Various types of plating techniques have made the metal more affordable for the masses. At the top of the plating pyramid is true gold-plate, which has a thickness of 2.54 microns. In contrast, pens described as being made using a process called gold flash can have as little as .05 microns of gold on their surfaces. Better are pens made of rolled gold or those described as being gold filled, which means a three-to-12-micron layer of 14- or 18-karat gold is bonded to a sheet of brass or some other harder metal.
As with sterling-silver pens, gold can be hammered from behind (repoussé) or above (chasing). It can also be engraved, pierced, or both. Piercing allows designers to create elaborate filigree effects, which are frequently set against black plastic barrels and caps so the gold paisleys, florals, and other motifs stand out.