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Hair coloring

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Hair colouring products generally fall into four categories: temporary, semipermanent, deposit only/demi, and permanent. All these hair colour products, except for temporary colour, require a patch test before application to determine if the client is allergic to the product.

"Hair lightening," often referred to as "bleaching" or "decolorizing," is a chemical process involving the diffusion of the natural colour pigment or artificial colour from the hair. This process is central to both permanent hair colour and hair lighteners.

All permanent haircolour products and lighteners contain both a developer, or oxidizing agent, and an alkalizing ingredient as part of their ammonia or an ammonia substitute. The purpose of this is to:

  • raise the cuticle of the hair fiber so the tint can penetrate,
  • facilitate the formation of tints within the hair fiber,
  • bring about the lightening action of peroxide.

When the tint containing the alkalizing ingredient is combined with the developer (usually hydrogen peroxide), the peroxide becomes alkaline and diffuses through the hair fiber, entering the cortex, where the melanin is located. The lightening occurs when the alkaline peroxide breaks up the melanin and replaces it with new colour.

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[edit] Temporary Hair Colour

The pigment molecules in temporary hair colour are large and, therefore, do not penetrate the cuticle layer, allowing only a coating action that may be removed by shampooing. An example of use of temporary hair colour is for Halloween costumes.

Acid dyes are used to coat on the surface of hair, since acid dyes have a low affinity to hair, thus can be removed after a shampoo.

Temporary hair colour is available in various product forms including rinses, shampoos, gels, and others. This type of hair colour is typically used to give brighter, more vibrant shades or colours such as orange or red, that may be difficult to achieve with semi-permanent and permanent hair colour. This phenomenon is due to the fact that temporary hair colourants do not penetrate the hair shaft itself. Instead, these dyes remain adsorbed (closely adherent) to the follicle and can be easily removed with a single shampooing. However, even temporary hair colouring agents can persist if the user's hair is excessively dry or damaged, conditions that allow for migration of the dye from the exterior to the interior of the follicle. While temporary hair colour products hold a lesser market than semi-permanent and permanent agents, they have value in that they can be easily and quickly removed without bleaching or application of a different dye.

[edit] Semipermanent

Formulated to deposit colour on the hair shaft without lightening it. This formula has smaller molecules than those of temporary tinting formulas, and is therefore able to penetrate the hair shaft. Has no developer, may be used with heat for penetration. It also lasts longer than temporary hair colour, keeping intact up to 8-14 shampoos.

[edit] Demipermanent

Uses a mild, creamy developer of a lower volume [3 to 7 volume or 1 to 3% H2O2] than permanent color. Lasts 2 to 3 months. Some demi products contain MEA's [an ammonia substitute] which helps with penetration and can lift natural color, but not seriously. Penetrates the hair shaft slightly, leaves hair shiny, covers/blends some gray.

The American Board of Certified Haircolourists and most major manufacturers of hair colour now say one should colour the new growth area with a permanent colour to cover gray and touch up or refresh the ends and length of the hair with a compatible shade of demipermanent colour to protect the condition of the hair.

Most hair colour manufacturers offer a demipermanent hair colour tube and a permanent hair colour tube within their product line. However, lately, some hair colour manufacturers like Compagnia Del Colore from Italy have come up with a very ingenious and cost-efficient solution for hair colourists. By using an activator or 7 Volume Peroxide (2.1% H2O2) you can now use the same permanent hair colour tube and convert it into a semipermanent hair colour tube.

[edit] Permanent

This is mixed with developer and remains in the hair shaft until new growth of hair occurs. It's used to match, lighten, and cover gray hair. Permanent hair colour generally contains ammonia, oxidative tints, and peroxide. The allergic reaction that comes from hair dye is generally one of sensitization to p-phenylenediamine (PPD). The reaction will most likely occur each time one dyes one's hair and will probably get worse each time. The sensitization from the ingredients in hair colour can extend to sensitization of other products of same or similar composition, including but not limited to the dye used in textiles, sunscreen, rubber, and/or certain medications.

Henna is a deposit-only hair colour whose active component, lawsone, binds to keratin and is therefore permanent. Henna may be removed with mineral oil; however, it is considered "permanent" because it does not wash out with shampoos or rinses. It is often mixed with other plant dyes, such as indigo, turmeric, and senna, to change the colour. Allergy to henna is much rarer than allergy to permanent hair colours. It is also considered a conditioning treatment.

Using a plant-based colour, specifically henna, can cause problems later when trying to do a permanent wave (perm) and other permanent hair colour. Discoloration can occur on hair that has been previously tinted with henna; hennaed hair typically cannot be curled. Breakage could also be an issue.

[edit] Special Effects

Special effects include highlighting and vivid, unusual hair colours such as green or fuchsia. Highlighting can range from temporary to permanent, using the techniques listed above and a special application process. The techniques required to apply highlighting can be difficult for an individual to perform upon him/herself. One can create looks that range from subtle highlights acquired during a day at the beach, to more dramatic looks, such as bold, chunky highlights.

The more exotic, bright dyes typically contain only tint, and have no developer. These are typically sold in punk-themed stores (such as comic book and music stores), but are rarely available at commercial hair dressers. Colours range from blood red to seafoam green. Many shades are blacklight reactive. Individuals with darker hair (medium brown to black) are advised to use a bleaching kit prior to tint application for the full effect of the colour. Some people with fair hair may benefit from prior bleaching as well, as the yellow undertones of blonde hair can make blue dye look green. These dyes are less permanent, and tend to "bleed" onto other fabric even when dry. Users should anticipate staining of light-colored pillows for a week or so after application.

[edit] Problems Related to Colouring Hair

When coloring one's hair it is always advisable to visit a professional hair colourist as there are many mistakes a person could make, as well as some serious consequences. The following are some of the problems that may occur as a result of applying hair colour:

  • Different color outcome compared to what was expected.
  • Breakage of hair stands.
  • Loss of hair.
  • Dry scalp.

[edit] Notable people who use hair coloring

[edit] See also

[edit] External links

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