The dyed hair is the procedure for changing the color of the hair . Common reasons for wanting to change color include covering gray hair or gray hair, changing to a color that is considered more fashionable or desirable, and restoring the original color of the hair after it has been bleached or bleached. induced by the action of solar rays.
Summary
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- 1 History
- 2 Types of hair dyeing
- 1 Temporary hair coloring
- 2 Semi-permanent hair coloring
- 3 Demi-permanent hair coloring
- 3 References
- 4 Sources
History
In the book ” The Eighteen Books of the Secrets of Art and Nature “, dating back to 1661, several methods are explained to change hair color to black, gold, green, red, yellow, and white. [one]
Hair dye, or hair dye, is a chemical preparation that is used to change the color of a person’s hair. Hair dye is used to cover gray hair as gray hair is a sign of aging. Young people can dye their hair as a way to be fashionable or simply because they want to do it to change their appearance.
The Romans are known to have been interested in altering hair color and from the historical information available it is known that they had created over a hundred recipes using natural ingredients. These preparations only allowed to darken the hair. During the Renaissance , blonde was a very popular choice because it was considered angelic and attractive.
In 1907, Eugene Schueller , the founder of the L’Oreal company , created the first synthetic hair dye, but was not very successful in sales.
Types of hair dyeing
The four most common types of hair dye are ‘temporary’, ‘semi-permanent’, ‘demi-permanent’ and ‘permanent’
Temporary hair coloring
Temporary hair coloring can be obtained by various techniques and methods including rinses, shampoos, gels, sprays and foams. Temporary hair color is generally brighter and more vibrant than permanent or semi-permanent hair colors. It is usually used to color hair for special occasions such as costume dances or Halloween .
Pigment molecules in temporary dyes are large and do not penetrate the cuticle layer of the hair. Color particles remain absorbed (adhered) to the hair and are easily removed by a single wash. It typically lasts from a few hours to a day.
Temporary hair dyeing can be maintained on hair that is excessively dry or damaged so that the pigment can penetrate into the hair.
Semi-permanent hair coloring
The dye for semi-permanent hair dyeing has smaller molecules than the temporary dye, and therefore partially penetrates the body of the hair . Therefore, the color withstands multiple washes, typically 4 to 5 shampoo washes or a few weeks. Some semi-permanent dyes may contain very low amounts of developer, peroxide, or ammonia, and are therefore safer for damaged or brittle hair. However, semi-permanent dyes may contain certain toxic compounds such as the P-Phenylenediamine compound or other similar ingredients.
The final color of each strand of hair will depend on its original color and porosity, so there will be slight variations in coloration in different areas of the head. Which provides a more natural appearance than a typical homogeneous color of a permanent coloration. However, it also means that white or gray hair will not be dyed the same shade as the rest of the hair. If there are only a few gray or white hairs, the effect will be enough to mimic them, but if the proportion of gray hair is considerable, there comes a point from which they cannot be camouflaged.
In these circumstances, it is possible to delay the need to resort to permanent dyes if semi-permanent colors are used as the base and reflections are added.
The semi-permanent color does not allow to lighten the hair.
Demi-permanent hair coloring
Demi-permanent hair dye dye is a permanent hair dye that contains an alkaline agent that is not ammonia (for example ethanolamine, or sodium carbonate ) and, although always used with a developer liquid, the concentration of peroxide Hydrogen in that developer may be less than that used with permanent dyes. Since the alkaline agents used in the demi-permanent are less effective in removing the natural pigment from the hair than ammonia, these products do not provide hair lightening during dyeing. Therefore, they cannot change hair color to a shade that is lighter than it was before the dyeing process and are less damaging to hair than permanent hair color.
The demi-permanent method is much more effective for covering gray hair than the semi-permanent method, however it is not as effective as the permanent one.
Demi-permanent have several advantages compared to permanent colorations. Since the natural color of the hair is not removed, the final color is less uniform or homogeneous than the permanent color and therefore presents a more natural tone; they are less aggressive with the hair and therefore safer, especially with damaged hair, they are also washed over time (typically about 20 to 28 shampooings), making growth at the root level less visible and it is easier if you want to change the tone of the hair later. Demi-permanent hair colors are essentially a permanent color and dark shades in particular may persist for longer times than those indicated on the tincture package.
