Before applying color, it is crucial for a hairdresser to assess hair porosity and elasticity. Porosity refers to how well the hair can absorb moisture and color. Understanding porosity helps the stylist determine the required processing time for the color to achieve the desired results. Hair with high porosity absorbs color quickly, potentially leading to over-processing, while low porosity hair may require additional steps, such as using heat, to allow the color to penetrate effectively.
Elasticity, on the other hand, indicates how much the hair can stretch without breaking. Checking elasticity is vital because hair that lacks elasticity may be more vulnerable to damage during the coloring process. Healthy hair with good elasticity can withstand the stresses of chemical treatments better than hair that is brittle or over-processed.
While the other choices include relevant aspects of hair care, such as scalp condition and client's preferences, they do not provide the same level of crucial information for color application as porosity and elasticity. These two factors are directly linked to the hair's health and ability to receive color, making them the primary considerations before beginning the coloring process.