Colors for hair are elements that allow to give our hair a certain color, which can be different from that given to it by melanin (think of a brunette woman who wants to experience a brown) or may be resetting the ex ante the color ” whitening “due to age. In any case, in the market there are numerous types of hair dyes: from those plants to metal ones, from those permanent to temporary ones, of stricarsi inside of the hair dye of the world is not always easy . Nothing prevents us, however, you can draw a small guide to choosing the best shade!
dyes for hair, from permanent to temporary
A first useful distinction of dyes it can be carried out on the basis of their “life” on our hair. In principle it is possible to distinguish four different dyes:
- permanent tints : are the colors with greater longevity on our hair. Their duration exceeds 2-3 months.
- semi-permanent tints are dyes intermediates between the permanent and temporary ones, with an indicative duration is between 1 and 2 months.
- gradual Colours : it is a favorite technique of many women, choosing the gradual dye to develop color gradually, thus avoiding too sharp a contrast between the situation ex ante and ex post.
- temporary Colours : is a soft dyeing, the duration of which fades within a few washings.
What are vegetable dyes
Provided that in the market there are many shades , distinguished according to their duration, we can forward us further into the world of dyes starting from the plant , so called because their substances applied to the foliage are extracted from plants and, as a rule, have reduced allergenic risks and irritating than metal ones.
in contrast, the benefits listed above collide with some “sin”: the vegetable dyes are actually less aggressive but, in addition, even less capable of giving the hair a new uniform color (are therefore mainly used to give color to your basic tone reflexes). Also, the colors plant have a more limited spectrum of colors than other colors . Still, these are colors that, as above, we can categorize the area of the “temporary”, since their application confers weak ties with the hair, and are therefore not permanent.
Among the vegetable dyes more notes , we can certainly indicate the presence of a number of products based on henna, a vegetable dye that can give the hair naturally dark, a red-coppery color (and hair blonde, reflections carrot-red color). Another particularly widespread plant substance is azulene, extracted from chamomile and able to donate some good reflexes to blond or light hair . The market also found the indigo plant dyes extracted from plants of the family indigo: indigo gives a blue color, and is generally used together with henna in order to give the hair a red-brownish tone.
What are gradual colors
the other major branch of the colors is represented by the gradual hair dyes, which can give the hair a desired color so – in fact gradual ( for this reason, various applications are usually required). The gradual hair dyes are composed of metallic salts that form metal oxides , or react with sulfur-containing compounds, such as keratin, cystine, cysteine. The mineral salts used are usually the acetate of lead, copper salts, nickel, cobalt, manganese. Through gradual colors accentuates the color of dark hair, covering the original color of hair.
What are the permanent tints
Introduced the above, let us now attend to the colors permanent , very special colors that in order to impart a desired result, must react chemically with other substances. Leaving aside for a moment the technical aspects – chemical, permanent colors are preferred by those women who want to have a wide range of colors and shades , covering gray hair with good levels of accuracy. It is also Products especially Budget compared to competitors, and very simple to use.
of course, in the face of such obvious advantages, we must unfortunately tolerate even some malus . First, it is possible – though not very frequent – the permanent dyes can cause allergies or irritation for this reason when using them is good to follow with precision several precautions, such as avoiding the use around the eye area (thus , never use these dyes to darken the eyelashes or eyebrows).
as for the more technical aspects , permanent dyes on the market are usually structured in such a way as to ensure a” mixed “composition primary dyes, couplers , ammonia, buffering agents (whose objective is to maintain a basic pH), antioxidant, oxidizing agents.
Still, always in relation to the colors permanent , it may be useful to try to go a little ‘well, simplifying the process through which the permanent color is “form.” To achieve this objective it is first necessary to mix the two parts of the kit that is deployed in the package (a first part determined by dyes, couplers, ammonia, buffer and antioxidant substances, the second part determined by oxidizing agents).
This” union “is able to produce a primary oxidation reaction on the intermediate , which in turn determines a reactive molecular species that binds the secondary intermediate (or coupler), thus generating a molecule formed by two benzenes linked by a group. Subsequently, form a second oxidation from which originates a dye molecule that has high molecular weight which can react with other couplers, generating complex compounds. in short, a series of fairly complex reactions, for those who are fasting in chemistry, taking place directly on the hair obtaining the desired color .
finally, remember that once it has been formed the dough color , we must apply it on the hair, leaving it to act between 20 and 30 minutes, allowing the penetration of intermediates in the structure of the hair. After the recommended period of application, you can proceed with the of the hair washing through the surface, to eliminate various precursors that do not have instead reacted. So, ultimately, we proceed with drying and styling.