The double-process method combines the use of lighteners, developers, catalysts and tints and toners. Double-process techniques are used to change the depth of color three or more levels, to impart or remove warm tones, and to create the platinum-blonde Marilyn Monroe look. The first step of double-process is to lighten the hair to the correct depth level. The second step is to apply a toner with the desired tonality.

Depth Level and the Stage of Decolorization (lightening):
When prelightening hair you must know at what stage of decolorization you need to stop to give the hair the tone desired. Black hair, for example, has pigment in all the secondary colors. When bleach penetrates the cortex, the color pigments break down, some more quickly than others. First the process removes green pigment and the hair turns red-violet. The violet pigment takes more time, but with patience it comes out. Gold is the result. The process can continue to end in the pale yellow stage. When you bleach red hair, then you start removing color from level four, the first color to appear will be red-orange. When you bleach blonde hair, it will first turn gold, then deep yellow, yellow and finally pale-yellow.

The chart above indicates the level of decolorization for each desired shade. In the chart the top line helps you identify the depth of color in your client’s hair and the depth of color desired. The bottom line shows the levels of decolorization needed for the desired color. For example, if a client has black hair and wants a lightest brown, decolorize the hair to stage five (orange) and apply a light brown tint. To subdue the orange use a drabbing color.