A collar pin is a piece of men's jewelry that holds the two ends of a dress shirt

Dress shirt

A shirt, or dress shirt in American English, is a garment with a collar, a full-length opening at the front from the collar to the hem, and sleeves with cuffs. Shirts are predominantly used by men, since women usually wear blouses...

 collar

Collar (clothing)

In clothing, a collar is the part of a shirt, dress, coat or blouse that fastens around or frames the neck. Among clothing construction professionals, a collar is differentiated from other necklines such as revers and lapels, by being made from a separate piece of fabric, rather than a folded or...

 together and passes underneath the knot of a necktie

Necktie

A necktie is a long piece of cloth worn for decorative purposes around the neck or shoulders, resting under the shirt collar and knotted at the throat. Variants include the ascot tie, bow tie, bolo tie, and the clip-on tie. The modern necktie, ascot, and bow tie are descended from the cravat. Neck...

. Functioning in a similar way as a tabbed collar, it keeps the collar in place and lifts the knot to provide a more aesthetically pleasing arc to the necktie.

A collar pin is between three and five centimeters in length and is one of three kinds:

• a barbell
  Barbell (piercing)
  Barbell style piercing jewelry is composed of a straight bar and with a bead on each end, one or both beads unscrewable for removal and/or changing of the beads. Often one of the beads is fixed, either via epoxy or welding, so that only one bead is used to install or remove the jewelry...
  
   whose ends screw off and is designed to pass through specially made eyelets in the ends of the collar
• a pin, similar to a safety pin
  Safety pin
  A safety pin is a simple fastening device, a variation of the regular pin which includes a simple spring mechanism and a clasp. The clasp serves two purposes: to form a closed loop thereby properly fastening the pin to whatever it is applied to, and to cover the end of the pin to protect the user...
  
  , that pierces the ends of the collar
• a bar with clips on both ends that grasp the ends of the collar

The latter two styles do not require specially made collars, but collar bars are generally not worn with buttoned-down collars and would be redundant with tabbed collars. Collar stays

Collar stays

Collar stays are shirt accessories.Collar stays are smooth, rigid strips of metal , horn, baleen, mother of pearl, or plastic, rounded at one end and pointed at the other, inserted into specially made pockets on the underside of a man's...

are not needed when using a collar bar.

External links

• http://www.gentlemansgazette.com/collarpin/
• http://www.gq-magazine.co.uk/style/style-shrink/expert-answer-/style-shrink-the-case-against-collar-pins
• http://trendzeta.blogspot.com/2009/11/please-bring-it-back.html