First, the role of dyeing primary colors
1, which is used as the base coat. When the hair has multiple colors, the base color is unified for further coloring.
2, used to cover white hair, there is white hair when dyeing hair, in order to cover, the dye paste will be prepared according to the proportion of white hair.
3. Use and supplement hair pigment ions. Simply put, when the hair is dull, the pigment ions in the hair have been lost. At this time, the effect of supplementing with primary colors is the best
Second, the types of hair dyeing
1, high-gloss dyeing method: first put the rubber cap on the hair, and then use crochet to pick the hair out of the small eyes of the rubber cap for dyeing. After washing, the effect is natural and there is obvious line feeling.
2, block dyeing method: the whole hair dye is coated on the hair to make it show the special shape of the block, usually used to create a stage effect.
3. Strip dyeing method: it is to dye the hair that needs to emphasize the line effect to enhance the line and three-dimensional sense of the hairstyle.
4. Spot dyeing method: This dyeing method is generally irregular, and there is no certain direction and order for dyeing hair. When you dye your hair, where do you think the hairstyle needs to stand out, just point the hair dye on this part.
Extended data:
Hazards of hair dyeing:
Secondary amine can easily react with epoxy, aldehyde and acid gas, and can be used as dye fixing agent to stabilize the adhesion effect of dyes. It can penetrate into skin and hair and stay for weeks, months or even years, and react with tobacco smoke or waste gas in the air to generate nitrosamines, which are a strong carcinogenic chemical.
It is reported that hair dyes are associated with a series of cancers, including breast cancer, bladder cancer, uterine cancer, brain cancer and leukemia. As early as 2009, a woman in Britain was at risk of blood cancer because she used hair dye more than 9 times in a year. A year later, the European Commission banned 22 hair dye products that may cause bladder cancer.
Hair dyes also contain heavy metal salts. Once it enters the human body, it is difficult to excrete it. If it accumulates in the body for a long time, it will cause poisoning, dizziness, headache, fatigue, numbness of limbs and other poisoning symptoms, and may enter the liver, kidney and brain, destroying the functions of these organs.
Experts advise you not to dye your hair. If you need to dye your hair, the interval between dyeing your hair should be at least 3 months, preferably in a professional barber shop. Do not bake oil one week before dyeing, and do not wash your hair on the day of dyeing. The oil secreted by scalp has protective effect; If the scalp has a wound ulceration, it is not suitable for dyeing hair.
If you wait in a smoky environment for a long time after dyeing your hair, you should wash your hair frequently and remove the harmful substances adsorbed on your hair in time. It's best to wear a hat when traveling in foggy days, and take off your coat immediately after entering the house to reduce the harm of dirty outdoor air to your body.
Baidu encyclopedia-hair dye