PSI Cosmetology Practice Exam

The double process technique is designed specifically to lighten hair before applying a new color. This procedure is typically used when the desired color is significantly lighter than the natural hair color or when creating very light shades, such as platinum blonde. During a double process, the first step involves using a lightener or bleach to lift the hair to the desired level of lightness. After achieving the appropriate lightness, a second application is done to deposit the desired color. This two-step process is essential because simply applying a lighter color over darker hair may not yield the intended results; the color could appear muted or overly dark, failing to achieve the desired vibrancy. In contrast, options like single process, glossing, and demi-permanent color all involve applying color directly to the hair, either to enhance the existing shade or to cover gray, without the initial step of lightening hair to a higher level. These options can deepen or change the tone of the hair but are not intended for significant lightening prior to color application, making them unsuitable for this particular question about lightening hair before depositing color.