Describe the 2X base in perm design.

• A. Measured with two full diameters of the rod, produces a looser curl, reduces lift, more hair wrapped
• B. Measured with one full diameter of the rod, produces a tight curl
• C. Measured with three full diameters of the rod, increases lift
• D. Measured with two halves of a diameter, increases lift

Answer: (A)

In perm design, base size describes how much hair sits on the rod at the scalp, measured in rod diameters. A 2X base means the base length is two full diameters of the rod. This longer base spreads the hair over a longer arc on the rod, so the curl formed is less curved—producing a looser curl. Because more of the hair is wrapped along the rod rather than lifted away from the scalp, lift is reduced. In short, two full diameters of base give a looser curl, less root lift, and more hair wrapped around the rod.