Which hair attribute determines the temperature setting on a curling iron?

• A. texture of the hair
• B. length of hair
• C. color of hair
• D. density of hair

Answer: (A)

Texture is the main factor that guides the temperature setting on a curling iron. Fine hair, with a small diameter, heats up and cools down quickly and is more prone to damage, so a lower temperature is usually safer and sufficient to form a curl. Coarse hair has a larger diameter and is more resistant to curling, often requiring higher heat to shape the curl properly, but still with care and protection to minimize damage. Medium texture sits between these extremes. Other attributes like length, color, or density don’t directly determine the heat setting in the same way; length affects processing time, color doesn’t reliably indicate heat tolerance, and density refers to how much hair there is rather than how it responds to heat.