What occurs when color or lightener application surpasses the line of demarcation?

When color or lightener application surpasses the line of demarcation, it results in what is known as overlap. This occurs when a new application of color or lightener is applied directly onto previously colored hair, creating a potential issue where the new color can affect the previously processed hair differently due to changes in porosity and texture.

Overlap can lead to various outcomes, including uneven results or excessive lightening of the previously colored part, as it may not react the same way as virgin hair. The line of demarcation represents the boundary between the newly grown hair and previously processed hair. Maintaining this distinction is important for achieving a consistent and harmonious color throughout the hair. It’s essential for haircolorists to be aware of this phenomenon to avoid undesirable results and to create a seamless transition in hair color.