Final answer:
The processing time for hair decolorization is influenced by the size of the cuticle layer, the presence of the medulla, the amount of product applied, and the amount of natural pigment present in the hair.
Step-by-step explanation:
The factors affecting the processing time when decolorizing hair include the size of the cuticle layer, presence of the medulla, the amount of product applied, and the amount of natural pigment. These factors influence the penetration and effectiveness of the decolorizing agent. The amount of product applied and the amount of natural pigment in the hair both affect the strength of the decolorizing process. More product and higher levels of natural pigment may require a longer processing time to achieve the desired result.
The size of the cuticle layer impacts how quickly and easily the decolorizing product can penetrate the hair shaft. A larger cuticle layer may slow down the process. The medulla, being the innermost part of the hair shaft, might not have a direct effect, but its presence indicates a thicker hair strand which could require more time for thorough penetration. The amount of product applied should be sufficient to saturate the hair completely for even decolorizing, and insufficient product can lead to patchy results and longer processing times. Moreover, the amount of natural pigment varies among individuals, which affects how long it will take to achieve the desired level of decolorization since darker hair has more pigment that needs to be removed.