What should be checked for prior to performing a chemical treatment on hair?

Prior to performing a chemical treatment on hair, assessing the hair's elasticity and porosity is crucial for determining how the hair will respond to the treatment. Elasticity measures the hair's ability to stretch and return to its original shape, which indicates its health and strength. If the hair has low elasticity, it may be more prone to breakage during chemical processes.

Porosity refers to the hair's ability to absorb and retain moisture and products. High porosity hair tends to absorb chemical treatments more quickly, which can lead to over-processing and damage if not approached carefully. Conversely, low porosity hair may resist chemical penetration, necessitating adjustments in application or processing time.

In summary, checking elasticity and porosity allows the barber or stylist to customize the chemical treatment to the specific needs of the hair, ensuring a safer and more effective outcome.