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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 cut part of the same piece of fabric used for the main body of the garment.

A collar may be permanently attached to the main body of the garment (e.g. by stitching) or detachable.

The Oxford English Dictionary traces collar in its modern meaning to c. 1300. Today's shirt collars descend from the ruffle created by the drawstring at the neck of the medieval chemise, through the Elizabethan ruff and its successors, the whisk collar and falling band. Separate collars exist alongside attached collars since the mid-16th century, usually to allow starching and other fine finishing.

During the Edwardian period and sporadically thereafter, ornamental collars were worn as a form of jewelry.

Collars can be categorized as:

Collars may also be stiffened, traditionally with starch; modern wash-and-wear shirt collars may be stiffened with interfacing or may include metal or plastic collar stays. Shirt collars which are not starched are described as soft collars. The shape of collars is also controlled by the shape of the neckline to which they are attached. Most collars are fitted to a jewel neck, a neckline sitting at the base of the neck all around; if the garment opens down the front, the top edges may be folded back to form lapels and a V-shaped opening, and the cut of the collar will be adjusted accordingly.

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Wikipedia