The world of hair coloring is filled with a plethora of options, and two common practices are using semi – permanent dye and bleaching. Many people wonder what happens when these two meet. This question is not as straightforward as it may seem. Understanding the nature of both bleached hair and semi – permanent dyes is crucial in determining the outcome. This complex interaction between the two can lead to various results, and exploring these will help us better manage and predict how our hair will look after the coloring process.
Understanding Bleached Hair
The Bleaching Process
Chemical Reaction: Bleaching involves the use of strong chemicals such as hydrogen peroxide and ammonia. These chemicals break down the melanin in the hair, which is responsible for its natural color. The process strips the hair of its pigment, leaving it lighter. For example, dark brown hair can be bleached to a blonde shade over several applications, depending on the starting color and the strength of the bleach.
Porosity Increase: As a result of this chemical assault, the hair’s cuticle layer is damaged. This damage makes the hair more porous. The cuticle, which is usually smooth and tightly packed in healthy hair, becomes lifted and rough. This new porous structure allows substances like dyes to enter the hair more easily. It’s like opening the doors of a house wider, making it more accessible to outsiders.
Effects of Bleaching on Hair Structure
Weakening: The chemical process of bleaching weakens the hair strands. The internal structure of the hair, including the cortex, which provides strength and elasticity, can be compromised. This means that bleached hair is more prone to breakage. You might notice that bleached hair feels more brittle and snaps more easily when combed or styled.
Dryness: Bleached hair also tends to be drier. The natural oils that keep the hair moisturized have a harder time adhering to the damaged cuticle. This dryness can make the hair look dull and frizzy, and it can further affect how the hair reacts to dyes.
Understanding Semi – Permanent Dye
Composition of Semi – Permanent Dye
Colorants: Semi – permanent dyes contain various colorants. These are usually smaller molecules compared to those in permanent dyes. The colorants are designed to coat the outside of the hair shaft and penetrate only slightly into the cortex.
For example, common colorants in semi – permanent dyes include direct dyes like nitro dyes and azo dyes. These molecules are able to provide color without the need for a developer like in permanent dyes.
Base Ingredients: In addition to colorants, semi – permanent dyes have a base that helps in the application and adherence of the color. This base often contains ingredients like conditioners. The conditioners in the dye can help to improve the feel of the hair during and after the coloring process. They can also play a role in how the color is absorbed and retained by the hair.
How Semi – Permanent Dye Works
Depositing Color: Semi – permanent dye works by depositing color onto the hair shaft. It relies on the porosity of the hair to hold the color. When applied to normal, non – bleached hair, the dye molecules attach to the cuticle and slightly penetrate the cortex. However, the color is not as long – lasting as with permanent dyes because it doesn’t form strong chemical bonds within the hair structure.
Limited Penetration: Unlike permanent dyes, semi – permanent dyes do not fully penetrate the hair shaft. They are more surface – based, which is why they eventually wash out over several shampoos. This limited penetration is an important factor when considering how they interact with bleached hair.
Interaction Between Semi – Permanent Dye and Bleached Hair
Increased Absorption
Porosity Advantage: Bleached hair’s increased porosity means that it can absorb semi – permanent dye more readily. The lifted cuticle allows the dye molecules to enter the hair shaft more easily. This can result in a more intense color payoff. For example, if you apply a semi – permanent purple dye to bleached blonde hair, the color may appear more vibrant than if applied to non – bleached hair.
Risk of Over – Saturation: However, this increased absorption also comes with a risk. The hair can become over – saturated with dye, especially if left on for too long. This can lead to an uneven color distribution or a color that is too intense and difficult to manage. For instance, if you apply too much semi – permanent red dye to bleached hair, it might turn out a much deeper red than intended.
Color Fading and Staining
Faster Fading: While semi – permanent dye may initially show a more vibrant color on bleached hair, it can also fade more quickly. The damaged structure of bleached hair may not hold the color as well over time. The colorants can be washed out more easily with each shampoo. This means that the beautiful color you achieved might start to fade after just a few washes.
Staining: There is also a possibility of staining. The porous nature of bleached hair can cause the dye to become trapped within the hair structure. This can lead to a situation where the color seems to “stain” the hair, even after attempts to remove it. For example, if you try to change the color of bleached hair that has been previously dyed with a semi – permanent dye, you might find that remnants of the old color are still visible.
Tips for Coloring Bleached Hair with Semi – Permanent Dye
Patch Testing
Importance: Before applying semi – permanent dye to your entire head of bleached hair, it’s essential to do a patch test.
Select a small, hidden section of hair, such as behind the ear. Apply the dye according to the instructions and observe the results. This will give you an idea of how the dye will interact with your bleached hair, including the color payoff and any potential staining or adverse reactions.
Checking for Allergies: Patch testing also helps in identifying any allergic reactions. Some of the ingredients in the dye, such as certain colorants or preservatives, may cause an allergic response. If you notice any redness, itching, or swelling in the patch – tested area, it’s best to avoid using that particular dye.
Preparation of the Hair
Deep Conditioning: Before applying the dye, it’s a good idea to deep – condition bleached hair. This helps to improve the hair’s condition and reduce its porosity slightly. You can use a deep – conditioning mask that contains ingredients like keratin, argan oil, or shea butter. Leave the mask on for the recommended time and rinse thoroughly. This step can make the hair more receptive to the dye and may also help in achieving a more even color.
pH Balancing: Bleached hair often has an altered pH level. You can use a pH – balancing product to bring the hair’s pH back to a more normal range. This can help in the absorption of the dye and can also prevent damage during the coloring process.
Application and Processing
Even Application: When applying the semi – permanent dye, make sure to distribute it evenly throughout the bleached hair. Use a tinting brush or your gloved hands to work the dye from the roots to the ends. Pay extra attention to the ends, as they are usually the most porous and can absorb more dye. Avoid applying too much dye at once, as this can lead to over – saturation.
Proper Processing Time: Follow the recommended processing time provided by the dye manufacturer. Leaving the dye on for too long can result in an overly intense color and potential staining. On the other hand, not leaving it on long enough may lead to a weak color payoff. Set a timer and rinse the dye out thoroughly with lukewarm water when the time is up.
Conclusion
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