Hair Dying Flashcards
Why is hair colored?
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The natural color of hair depends on
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eumelanin
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phaeomelanin
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makes brown to black hair shades while phaeomelanin is responsible for blond and red colors.
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You can have one or both melanin pigment types and the ratio and concentration of each determines your shade of hair color.
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The absence of both melanin types produces
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As the hair fiber grows/…..
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How bleaching and dyeing hair works?
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mixing the bleach in an alkaline solution.
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First, the hair cuticle has to be
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The oxidized melanin pigment is…..
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The complete bleached hair is ….. rather than pure …. colour.
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Bleach reacts more readily with the…..
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Some gold or red residual color may remain after lightening depending on how much phaeomelanin your hair follicles make.
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This process may be enough for those who just want their hair lightened.
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Usually a finishing dye is added why
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to hide the ….. color of the keratin which does not look a very
natural ……
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Again, the cuticle has to be opened up for the dye to get inside the hair fiber using…..
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In this process peroxide is used as a developer or oxidizing agent to
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…….. a new permanent color is bonded into the hair cortex.
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the technique is a two step process:
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At the end of the process, an acid shampoo or a conditioner is used to …..
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To go from dark hair to very light hair a pre-bleach is usually required to…..
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Hair coloring preparations
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There are four major classes of coloring and decoloring agents:
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Hair colour shade is described by a range of….
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Temporary and semipermanent products do not ….. the natural colour at all.
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The rigorous lightening can only be achieved by…..
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plant derivatives,
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metallic dyes
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Bleaching agents
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Chemical bleaches must be:
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Non toxic,
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Mild in action
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Free of harmful residues
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…….fulfils the requirements because after releasing the oxygen it leaves no residue but water.
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It is identified by volume content (number of volumes of available oxygen liberated by a given volume of the solution)
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3-4% solution generate ……
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5-6% generate….
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Steps of hydrogen peroxide bleaching
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The degree of bleaching depends on:
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….. is activated by the addition of few drops of
ammonium hydroxide or ammonium persulfate powder
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time of contact.
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penetrate and attack the keratin structure
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gradually lighten the shade of hair by oxidizing the melanin
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Procedures
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….. of NH4OH should be added to 1oz of hydrogen peroxide
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The mixture should be applied to the ……
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Advantage of procedure
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DisAdvantage of procedure
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Repeated application to the same portion of hair
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No second shampoo is required
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Hairs are kept ….. with the solution until the desired tint is obtained
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The hair should be well shampooed and dried
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Preparations
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A-Brightening rinse
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poured over the hair until the desired shade is seen R/
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Hydrogen peroxide.
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Ammonium hydroxide
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Hydrogen peroxide can also be used in the form of :
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cream
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powder
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oil bleach
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shampoo.
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ammonium soap as ammonium oleate to be mixed with
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……l to be mixed with hydrogen peroxide and ammonia; white henna)
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tablet made of peroxide and urea to be dissolved at the
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moment of use),
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PERMANENT DYES .
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molecules are allowed to diffuse into and
through the hair, then under a series of chemical reactions, generate
…….molecules incapable of being washed out.
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PERMANENT DYES The process requires three constituents and three steps:
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are the substrates coupled by oxidized intermediate and give a colourless diphenylamine, the leuco (colorless) form of the final indo dye.
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is the most commonly used. It is oxidized by alkaline peroxide and form an intermediate reactive species (diimine) (slow step).
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para-phenylenediamine (PPD,
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usually come packaged as two bottles.
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The actual dye has to be mixed with the…..
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There are three generations of permanent hair dyes:
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…….. are referred to as Level 3 colorants and use ammonia and 30 vol.
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H2O2 and need ……..min. to achieve.
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Recent improvements to this category include the use of an …… (…….to replace some of the ammonia
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Demipermanents or Level 2 colorants which apply ….
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are more suitable for gray hair and take shorter time (10 min.).
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….. will lighten the hair somewhat, but unless the hair is prebleached, the degree of lightening is modest and limited..
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Hair dyeing frequency
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you should not dye your hair more than….
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oxidative colorants usually last a ……
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more frequent applications may result in …… hair damage.
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Pharmaceutical forms of permanent colorant
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products come in many forms: liquid, cream, gel, and aerosol.
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dye base
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…. the dye and developer are kept separate inside the can in two individual plastic containers.
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When you press the valve construction on top, ……
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…… mixes the two together as they come out of the can.
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Advantages of aerosol permanent dye:
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Things that can go wrong with permanent hair dyes
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SEMIPERMINANT HAIR DYES
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There is no wasted dye.
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…….are relatively unstable. old hair dyes should be thrown away.
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if the reaction is not conducted under optimal concentration, temperature, contact time.. etc. the end result can be…..
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if they are applied inappropriately they…..
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if you do not like the end color, it is difficult to……
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Reapply a new dye, (severely damage hair).
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Either bleach out the hair dye
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These are large molecules but can penetrate and diffuse throughout the …….
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These do not involve a developer like peroxide to fix the color
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The dyes are called …… because the coloring changes will survive through several washes
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The time it lasts depends in SEMIPERMINANT HAIR DYES
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usually it resists 6-8 shampooings
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can produce an immediate change or the change may be more gradual, developing with time and multiple reapplications
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…….. over weekly intervals will gradually deepen the color to be like that achieved with the longer time, ……
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Because color change is less noticeable with repeated short applications over time, it is usually preferred by those with …..
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The great majority of these dyes belong to the following chemical
classes:
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are the most versatile semi- permanent dyes, are easy to synthesis, and have colour range from yellow to violet.
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have colour range from yellow to orange
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Aminoanthraquinones
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these complete the colour palette by
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The problem with semi permanent hair dyes:
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They usually do not reproduce dark brown and black shades that can be readily obtained with permanent dyes.
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➢It is better suited for those who want lighter shades of color and for those with mousy and gray hair.
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TEMPORARY COLOURINGS
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colour rinses’
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generally used for a specific event or occasion.
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removed by the first shampooing
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high molecular weight and do not penetration into the ……
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are acid dyes with minimal affinity for the overall anionic nature of hair, ……
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products formulated solely with D&C and/or FD&C dyes do not …
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cause allergy and you have to check 48 hr prior to application,
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application of heat after treatment with temporary colorants may significantly …… the durability of the dyes.
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VEGETABLE HAIR DYES
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METALLIC HAIR COLORANTS
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HAIR DYE REMOVAL
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Organic hair dyes, such as dyes made from indigo, camomile, logwood, walnut hulls, henna and many other plant sources were popular.
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….. is made from the ground up dried leaves and stems of the henna plant (Lawsonia inermis) that grows in North Africa and the Near East.
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usually green to look at in powder form because the dried leaves are green but the colour produced is red.
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…… usually made into a paste with hot water and then painted onto the hair.
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The degree of color depends in part on the ….
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The effects of henna hair dyes are …… and can build up ….. and by repeated application over several weeks
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The result is relatively ….. and can look quite attractive when done properly.
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It is a ……. but the results can last a long.
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The end result can be improved by adding……
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Additionally, the application is relatively simple and quick, easily added to a home hair care routine.
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VEGETABLE HAIR DYES
Disadvantages
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highly allergenic for some people.
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Variable and limited shade
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Messiness
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……… when applied to blonde hair will dilute the color and make the hair a lighter shade of blonde.
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Metallic hair colorants generally use….
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The colour is developed by the slow formation of…..
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METALLIC HAIR COLORANTS
Disadvantages
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limited and variable results
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uneven shade development
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possible sulfide odour
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HAIR DYE REMOVAL
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Sometimes necessary because of either a mistake or an undesirable result.
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The degree of difficulty in removal is related to…..
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Permanent hair dye
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Once hair is colored with …… hair dye, you are essentially stuck with the results.
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There are two options for corrective action:
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chemical treatment
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re-dying with another shade.
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……. the answer is much easier. The dye will come out gradually with regular washing.
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If you want to speed up the process a little, you can try applying some
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