Which type of dye produces increased absorption with each application?

Progressive dyes are designed to build up color with each application. The mechanism behind this type of dye involves the gradual darkening of the hair as the dye is reapplied. Unlike other types of hair color, progressive dyes create a chemical reaction that allows the color to penetrate the hair cuticle more thoroughly over time. This results in a cumulative effect, where the hair absorbs more dye, leading to a richer, deeper color with each usage.

This characteristic makes progressive dyes particularly appealing for individuals looking to achieve a darker shade by gradually enhancing the color without needing to apply very harsh chemicals in a single session. The other types of dyes, such as semi-permanent, plant-based, and direct dyes, do not work in this building fashion; they tend to deposit color in a more immediate way without the same level of absorption increase over successive applications.