Which testing technique is commonly used to determine hair type?

The elasticity test is an effective technique for determining hair type, as it evaluates the hair's ability to stretch and return to its original length without breaking. Hair elasticity is influenced by the hair’s moisture content, health, and overall condition. By assessing elasticity, professionals can identify whether the hair is healthy and well-moisturized, prone to damage, or lacks resilience, which can significantly impact styling and care recommendations.

In contrast, the other tests serve different purposes. The porosity test measures how well hair absorbs and retains moisture, providing insights into the hair's condition but not directly indicating its type. The texture test evaluates the diameter of individual hair strands (fine, medium, coarse), while the density test assesses how closely packed the hair strands are on the scalp, indicating how full or thin the hair appears. Each of these tests provides valuable information, but the elasticity test is specifically relevant for understanding the overall health and strength of the hair, making it essential for determining hair type.