Bleaching powder is a powerful agent that is used to strip color from the hair. This powder alone is not enough to lighten the hair, however, and it must be mixed with developer, or hydrogen peroxide, to activate the lightening process. For the best results, you should choose a powder/developer combination that is strong enough to produce the desired color yet gentle enough to be used safely.
Consumers have two main options when choosing a bleach for the hair: they can choose a bleaching kit from their local supermarket or make their own. Bleaching kits usually consist of the powder, liquid developer and gloves.
Most pre-assembled kits come with a strong bleaching powder and a 20-volume developer. Developer is available in one of four strengths: 10-, 20-, 30- and 40-volume. A 40-volume developer will lift at least six levels of color, which means that a person who has black hair will be able achieve a dark blond through one process of using it. Bleaching agents, however, never completely stop lifting color until they are dry to the touch.
On average, a 20-volume developer will lift two to three levels of color. If your natural hair color is a light brown, you should be able to achieve a light blond after 35 minutes of using a 20-volume developer. If your hair is a darker brown, however, 20-volume developer might not be strong enough to achieve the desired results.
If you need more lifting power, you might benefit more from choosing a bleaching powder and developer from your local beauty supply store. When choosing one, it’s important to understand that most powders are fairly similar. They are usually made up of calcium chloride, calcium hypochlorite, and calcium chloride hypochlorite, although potassium persulfate, ammonium persulfate, and sodium persulfate also might be used.
The main difference between bleaching powders is their consistency and ability to retain moisture. Bleach deactivates when it dries, which is why it is important to choose a powder that contains moisturizing agents. Some powders are also formulated to be dust-free, creamy, and easy to use. It will be very difficult to use a product that mixes into a thin, watery consistency. Non-drip formulas are much more user-friendly.
Depending on the color and texture of your hair, you might want to choose an extra-strength powder. Such formulas are able to lift as many as seven levels of color, which would take black hair to a medium blond. To achieve these results, the powder will need to be activated with a 40-volume developer.
The last thing to consider is whether a powder is designed to be used off or on the scalp. If you will be bleaching your hair one uniform color, you need a product that is safe to use on the scalp. Off-scalp powders are best when used to highlight the hair. Choosing a bleaching powder that is safe for the skin will ensure a more comfortable and effective bleaching process.