Since ancient times artists have used precious metals to create or enhance artwork. Both gold and silver, among other metals, have been used in making art.
From medieval times to the present, silver has often been used in making delicate expressive drawings. One of the most often used techniques is “silverpoint”. This is where a thin pointed strand of silver wire is used as a drawing instrument. Sorta like the lowly graphite pencil of today, the silverpoint tool was used both in “sketching” outlines for further painted artwork and to complete “finished” pieces of art. The silver that was rubbed off the piece of silver wire, with each stroke, stuck to the treated surface (paper, gessoed canvas etc). Over a period of weeks, the silver would tarnish, just like silver candlesticks do today. The soft grayed silver tarnish would give drawings a lovely “glow”. This is a nice Wikipedia article on the practice: http://en.wikipedia.org/wiki/Silverpoint
One of the most enduring metals used in art is gold.....leaf to be exact. As opposed to silverpoint's use of silver wire to make a drawing, gold leafing has been used as a covering, in both 2D and 3D artworks. It can be applied both to a surface of a canvas or paper and onto a sculpture with many details. The main technique for gold leafing is to make the surface you want to cover “sticky” with some sort of liquid adhesive, and apply the extremely thin sheets of gold leaf. After it is dry, a gold leaf coat can be “burnished” to enhance the smoothness of the leafing, and increase the shine. Of course as with any medium, there are a multitude variations on how the gold leaf can be finished, with many different effects. Usually, after the gold leaf is completely finished, a varnish is applied to protect the fragile surface.
This detail of a coat of arms shows how lovely a bit of gold leaf can be. Incorporated into a graphic design, like a coat of arms, gold leaf is a beautiful highlight, that will make most anything look richer. If left un-burnished, the gold leafing will refract light in small sparkles. If the gold leaf is burnished.....or smoothed.....then it will be more mirror like in it's shine.
The coat of arms at the top of this post was completed using gold leaf and oil paints. It has the extra added twist of being done in a “reverse glass” technique. This is painting on glass, but on the reverse side of the glass than it will be viewed. This means that all the normal order of painting is also reversed.....details are put on first, then middle ground items and finally background items. The gold leafing is added last. If you don't go crazy first.....it's a great quirky technique!