The wash test involves washing the hair to evaluate its response to water and shampoo. It helps determine how the hair reacts to washing, whether it maintains its texture, luster, and overall quality after being cleaned. This test helps in assessing the hair's durability and ability to withstand washing without significant damage or change in quality.

The bleach test involves applying bleach or a chemical solution to a strand of hair to observe its reaction. This test helps identify whether the hair is genuine human hair or if it contains synthetic or mixed fibers. Human hair typically reacts differently to bleach compared to synthetic fibers, allowing for differentiation between the two.

The burn test involves burning a small sample of hair to observe its reaction to heat. It helps determine the hair's composition and authenticity. Human hair usually produces a distinct odor of burning hair and forms a residue of ash, while synthetic fibers may melt, emit a different odor, and form hard beads or residue.

The cuticle test involves examining the hair with scissors to assess the condition of the cuticle, the outermost layer of the hair shaft. This test helps determine if the cuticle is intact, smooth, and aligned along the hair shaft, which is an indicator of good quality. Damaged or disrupted cuticles may indicate poor-quality or processed hair.