Candle wick

wick of a candle

Wick in a rolled beeswax candle

A candle wick is a string, cord, or wooden object that holds the flame of a candle. A candle wick works by capillary action, drawing ("wicking") the fuel to the flame. When the liquid fuel, typically melted candle wax, reaches the flame it then vaporizes and combusts. The candle wick influences how the candle burns. Important characteristics of the wick include diameter, stiffness, fire-resistance, and tethering.

Dipped candles hanging by their wicks

Large diameter wicks typically result in a larger flame, a larger pool of melted wax, and the candle burning faster. Candle wicks are normally made out of braided cotton, and may contain a stiff core. This core was traditionally made of lead, however, lead wick cores have been banned in the U.S. for several years by the Consumer Product Safety Commission, due to concerns about lead poisoning. Zinc is often used as a safer replacement for lead in this application. (The two may be differentiated by the way they write on paper – lead will, zinc won't.) Other core stiffeners, such as paper and synthetic fibers, may also be used.

Most candle wicks are impregnated or coated with wax to provide the initial fuel source when the candle is lit. While the wick is consumed in the process of burning a candle the real fuel for the flame is the melted wax. As such all wicks are treated with various flame-resistant solutions in a process known as mordanting. Without mordanting the wick would be destroyed by the flames and the flow of melted wax to the flame would cease.

Wicks are sometimes braided flat, so that as they burn they also curl back into the flame, thus making them self-consuming. Prior to the introduction of these wicks special scissors were used to trim the excess wick without extinguishing the flame. However, the process of triming a candle's wick with scissors usually extinguished it anyway.

In tealights the wick is tethered to a piece of metal to stop it from floating to the top of the molten wax and burning before the wax does. Candles designed to float in water require not only a tether for the wick, but also a seal on the bottom of the candle to prevent the wick from wicking water and extinguishing the flame.

In some birthday candles, the wick is a stub. This limits how long the candle can burn.

Wicks can be made of material other than string or cord, such as wood, although they are rare.