NIC Barber Written (Theory) ExamHair Care ServicesMedium

A client has very coarse, resistant hair and desires a permanent wave with a strong, firm curl. Which type of perm rod would be most effective in achieving the desired curl pattern?

  1. ASoft bender rod
  2. BStraight rod
  3. CLarge diameter rod
  4. DConcave rod
Show answer & explanation

Correct answer: D. Concave rod

Concave rods produce a tighter curl in the center and looser curls on the ends, which is ideal for creating a strong, firm curl, especially on coarse, resistant hair where a tighter wrap is beneficial for better saturation and processing.

Why the other options are wrong

  • A. Soft bender rods are flexible and create soft, irregular curls or waves, not a strong, firm curl.
  • B. Straight rods produce a uniform curl from scalp to ends, which can be firm but may not provide the desired tightness for coarse, resistant hair compared to concave rods.
  • C. Large diameter rods create larger, looser curls or waves, not a strong, firm curl.

Concave Perm Rods

Perm rods that are smaller in diameter in the center and larger on the ends, creating a tighter, firmer curl in the middle of the hair strand and a looser curl at the ends. They are effective for producing strong, consistent curl patterns.

  • Most commonly used type of perm rod.
  • Ideal for achieving tighter curls and body.
  • Suitable for various hair lengths, especially medium to long.

Memory trick: Concave creates core curls.

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