so what are cufflinks?
Cufflinks are handy little devices used to keep the cuffs on the sleeves of your dress shirts together. They are a H-shaped affair, in two styles. The most common in my (limited) experience is a folding style, which has a hinge on one side, connected to the shank (the middle bit of the H); the hinged leg folds into the shank, forming a T-shape that slips through the slits in your dress shirt, then unfolds to hold the cuffs together between the legs of the cufflink. Another style is simply linked buttons which lock together at the shank. The cufflink's body is often some precious metal, and the non-hinged leg of the cufflink's H is decorated somehow; the cufflink is semifunctional jewelry, and so can be as gaudy or austere as the wearer wishes it to be. The size of the cufflink, of course, ranges depending on what sort of decoration the cufflink bears, but in general they are between the size of a US nickel and a normal men's shirt button.
the history of the cufflink
Cufflinks began to appear in the 16th century as purely functional devices; by the 17th century, cufflinks made with precious metals and festooned with jewels had begun to be used by nobility. A century later, the French cuff began to appear; this is the style of dress shirt which requires cufflinks to hold the cuffs of the sleeves together. By the mid 1800's this style of dress shirt became the standard.
In the late 1800's and early 1900's, cufflinks became very popular. No longer used just by royalty, cufflinks made from chromed metal and incorporating glass and plastics made stylish cufflinks affordable to the common man. Women began wearing cufflinks as well when they began to move into the white collar workforce in the 1930s and wore dress shirts similar to those worn by men. Cufflinks styled expressly for women were created because of this.
However, as the business world began to make its way from the suit and tie to business casual in the last 20 years, the cufflink went from neccessary and fashionable accessory to sitting unused in the bottom of sock drawers. While they have enjoyed a brief resurgence in the past few years, and will always be used in situations where only a dress shirt will do, cufflinks will probably never regain the ubiquity they enjoyed in the last century.
The decrease in popularity of cufflinks is really too bad. I remember seeing my dad put on his suit and tie (cufflinks? of course!) before he went to work every day, and thinking that's what a job is. It's the place you go almost every day where you have to wear a tie and those cool cufflinks. I always thought it was one of those uncomfortable, but neccessary things grown ups have to do. Turns out the grown ups rarely have to wear suits and ties anymore. He always said a well tailored suit is more comfortable than any pair of jeans and a t-shirt. I was sort of looking forward to being forced to wear that white collar uniform.