Regarding hair dyeing, do you also have such a problem-

Obviously, I carefully selected the reference image of the color, and I double-checked with Tony, but when I finally dyed and dried my hair, I found that the color was very different from the model on the packaging. I chose the same shade, but why is the effect so different?

In fact, the final color of your hair depends not only on the hair dye itself, but also on your hair type, undertone, and even the way you work.

Source: Social platform

Today, let's learn the scientific secrets behind hair dyeing and tell you why there is always a huge gap between the "buyer's show" and the "seller's show"!

Why you chose the hair color

Will it always roll over?

Why does the color of the dyed hair often not match the color card?

That's a good question.

First of all, a problem that can never be avoided is that the color card is a printed matter, and even if the ink used in it is the same substance as the hair dye, the effect of printing on paper is different from the effect of dyeing on hair. What's more, the ink used in most prints is just a mixture of several standard colors, and it is inevitable that there will be color differences in the final effect if you try to simulate the actual color color as much as possible.

Now the question is, why does the same hair dye make such a big difference when used on different people's hair?

The two main reasons are hair quality and the hair coloring process.

Although the main component of everyone's hair is keratin, keratin is a general term for a large group of proteins, and the amino acids that make up each person's hair keratin are not exactly the same, plus everyone's environment is different, these differences can affect some of the properties of hair. For example, some people's hair is highly absorbent, while others have dry hair.

These differences in properties are reflected in the adsorption of the hair, and the final hair dye will make a significant difference in the effect on the hair.

As for the hair dyeing process, it is not difficult to understand. Every time a barber dyes his or her hair is an independent work, no matter how skilled a barber is, there is no guarantee that the process will be exactly the same every time. The original color of the hair dye will only change to the final color after a chemical reaction under high temperature conditions, and the slight difference in reaction time and reaction temperature may affect the final effect.

In short, the effect after dyeing hair is not the same as expected, there are so many possible factors that it is difficult to say which link went wrong.

Colorful hair dye

What kind of damage can it do to the scalp?

Compared with the color problem, more people are worried about the damage to the hair when dyeing their hair.

Before understanding this problem, it is necessary to take a look at the principle of hair coloring.

The current hair coloring techniques are mainly divided into two main categories, one is to bleach the hair first and then dye it with a new color, and the other is to color the hair directly. The former hair dye effect is permanent, and only when new hair grows back, it will return to its original color; The latter effect lasts for a relatively short period of time, with some being able to withstand more than a dozen shampoos, and some even being washed off in just one wash.

It is not difficult to see from the process of dyeing that the longer the hair dye method is retained, the more significant the damaging effect on the hair. In barbershops, the reagent for bleaching hair is usually hydrogen peroxide, which can not only destroy the melanin in the hair, but also cause some damage to the protein of the hair itself.

At the same time, if you want to keep the hair dye for longer, you need to lift the hair cuticle on the surface of the hair, and the hair cuticle is the protective layer for the hair, although it will be closed again after dyeing, but the damage is already inevitable. In addition, hair dyeing usually requires heating, not only to allow the hair dye to react, but also to improve the binding force of the hair and the hair dye. When heated, the proteins in the hair also denature.

In addition to the damage to the hair, the composition of the hair dye is also worth noting. The main ingredient of many hair dyes is azo dyes, which have a relatively high risk of allergies, so some people will experience itchy scalp after dyeing their hair, which may actually be an allergic reaction.

By the way, some people experience itchy or even redness when wearing new clothes, which may also be due to an allergy to azo dyes in clothes. If this phenomenon does not subside for a long time, then it is time to see a doctor.

Dye your hair without overturning, try to do so

There are so many cases where hair dyeing can overturn, what are the lightning protection measures for beauty lovers?

The most important thing to do is not to challenge a relatively unusual hair color. For hairdressers, the more unfamiliar the shade, the more difficult it is to debug, and the greater the possibility of eventually overturning.

If you are prone to allergies, you can choose milder hair dyes and avoid using azo dyes to avoid allergies.

Finally, if you just want to maintain a special style at a certain stage, you may want to consider temporary hair coloring options. It's really overturned, and after washing, it can be restored to its original state, so that it won't keep sighing at the overturned hair.

Bibliography

[710]Bhushan B. Nanoscale characterization of human hair and hair conditioners[J]. Progress in Materials Science, 0, 0(0): 0-0.

Planning and production

Author丨Sun Yafei is a distinguished research assistant at the Institute of History of Natural Sciences, Chinese Academy of Sciences, and a Ph.D. in chemistry from Tsinghua University

Audit丨Feng Jun, Deputy Chief Physician of the Department of Dermatology, General Hospital of Datong Coal Mine Group Co., Ltd

According to Popular Science China