Making a cameo is a laborious and highly skilled craft dating back to about 300BC.
The most common material used to produce modern cameos is carnelian shell, which has a peachy orange colour inside.
The top white layer is carved away with a sharp chisel to reveal the contrasting lower layer. This method creates a relief, or positive, image.
Some cameos are intaglio, which give a negative image.
Intaglios were used in signet rings and seals as signatures, used by pressing the design into wax or other soft substances.
When we think of cameos, we envisage an image of a female head and shoulders but cameos have a far more reaching use of imagery.
Romans would wear cameo rings or earrings made from agate, onyx, jasper, sardonyx and other precious stones, depicting rulers or deities to advertise their status and wealth and to profess their devotion to their gods.
Romans also produced cheaper versions in glass with images of themes from mythology, beautiful women and biblical events.
They also produced glassware with images of gods, flowers and cherubs.
The most famous extant example of Roman cameo glass is the Portland Vase, which may date between AD1 and AD25.
It is made of violet-blue glass with white overlaid images of a single continuous scene with seven human figures, a large snake plus two bearded, horned heads.
In the 1770s, this vase served as inspiration for Josiah Wedgewood to produce his Jasperware pottery. He produced teapots, vases and cameos, most in in pale blue, which became known as Wedgewood blue.
Wedgewood went on to produce objects in dark blue, lilac, sea green, black and yellow. The pale blue, however, remains synonymous with Wedgewood.
Relief decorations in white contrast with the background colour to give a cameo effect. Wedgewood also produced a ceramic a copy of the Portland Vase.
There was a revival of wearing cameos during the Renaissance and again in the 18th and 19th centuries. Napoleon wore a cameo to his wedding and founded a school in Paris to teach young apprentices the art of cameo carving.
Queen Victoria often wore cameos. This mass production and a revival of the art form.
The Whanganui Regional Museum has two carnelian shell cameos. One shows a bishop saint, complete with mitre, shepherd's crook and halo. The other is a head and shoulders of a haloed saint with a cross in the background.
The museum also has a collection of plaster stamps with carved relief figures of individuals or scenes from Greek or Roman mythology.
They are souvenirs collected by wealthy young men (and the occasional young woman) who travelled around Europe on the Grand Tour, beginning in the mid-18th century.
When visiting Pompeii, tourists could purchase cameos made from the lava from the 79AD eruption.
They were light, cheap and they travelled well.
Their owners often glued the cameos into scrapbooks, or framed, to create a record of their adventures abroad.
Cameos are still produced today in Italy. Torro Del Greco, near Naples, is one such town where there are generations of craftsmen and women making cameos, employing methods used for centuries.
These artisans supply modern designs for such companies as Dolce & Gabbana, Oscar de la Renta and the Breuget Watch Company, giving a centuries-old tradition a modern twist and keeping the craft alive for generations to come.
*Kathy Greensides is the collection assistant at Whanganui Regional Museum