Hair Cutting Techniques

Hair Cutting Techniques

Chapter Introduction

Hair cutting is the foundation of the hairdressing profession. For the Red Seal exam, you must master not only the technical gestures, but also the terminology, design principles, angles, tensions, and applicable safety standards. This chapter covers all the theoretical and practical knowledge required for the "Hair Cutting" section of the interprovincial exam.

In Canada, hair cutting is governed by the hygiene and safety standards of the Canada Labour Code (for establishments under federal jurisdiction) and by provincial public health regulations. However, for the Red Seal exam, you must know the universal principles of cutting, the tools, the basic and advanced techniques, as well as proportion calculations and cutting angles.

1. Fundamental Principles of Cutting

1.1 The Five Elements of Hair Design

Every cut is based on five interdependent elements:

1.2 Hair Classification

The cut depends directly on hair type. The most widely used classification system in Canada is the Andre Walker system (modified):

Important for the exam: Hair diameter influences the cutting angle. For coily hair (type 4), the cutting angle must be more open (45° to 90°) to avoid the "stair-step" effect when drying. For straight hair (type 1), an angle of 0° to 45° is recommended.

1.3 Cutting Angles: The Degree System

The cutting angle is measured in relation to the projection of the section (elevation) and the inclination of the shears. The following table is essential:

Formula for calculating the effective angle:

When you cut with a shear inclination of Ω degrees relative to the section, the total angle is:

Total angle = Elevation angle + (90° − Ω)

Example: 45° elevation, shears inclined at 30° → Total angle = 45° + (90° − 30°) = 45° + 60° = 105°.

1.4 Tension and Section Control

Tension is the force applied to the section during cutting. It is measured on a scale of 1 to 10:

Golden rule: Tension must be consistent throughout the entire section. A tension variation of more than 2 points on the same section creates visible irregularities.

2. Cutting Tools and Equipment

2.1 Shears: Types and Uses

Maintenance standard: Shears should be sharpened every 3 to 6 months depending on frequency of use. A simple test: cut a wet hair 2 cm from the tip — if the hair deforms, sharpening is needed.

2.2 Razors and Clippers

Conversion calculation: Length in mm = Guard number × 3.175 mm.

Example: Guard No. 4 → 4 × 3.175 = 12.7 mm. ✓

2.3 Combs and Accessories

3. Basic Cutting Techniques

3.1 The Flat Cut (0°)

Principle: The hair is combed flat against the head, without elevation. The cut follows the natural contour of the skull.

Procedure:

Application: Bob cuts, clean nape cuts.

3.2 The Classic Graduated Cut (90°)

Principle: Each section is elevated to 90° relative to the head. The cut creates uniform length over the entire head.

Procedure:

Calculation of resulting length:

For a section of initial length L and an elevation angle θ, the visible length after drying is:

L_visible = L × cos(θ)

Example: L = 10 cm, θ = 90° → L_visible = 10 × cos(90°) = 10 × 0 = 0 cm (the length is perpendicular to the head, therefore not visible from the front).

3.3 The Tapered Cut (Texturizing)

Principle: Reduce volume and create movement without changing the overall length.

Techniques:

Volume reduction percentage:

3.4 The Reverse Graduated Cut (135°)

Principle: Sections are elevated beyond 90°, creating a pronounced graduation with more lightness at the crown.

Procedure:

Caution: This technique requires great precision. A 15° error can create a visible "hole" in the cut.

4. Advanced Techniques

4.1 Razor Cutting

Principles:

Pass speed and effect:

4.2 Clipper Cutting

Techniques:

Standard fade sequence:

4.3 Layering

Types of layers:

Calculating the number of sections:

For an average head (diameter 18 cm), the number of sections needed is:

N = (Circumference / Section width) × 2

Example: Circumference = 56 cm, section width = 2 cm → N = (56 / 2) × 2 = 56 sections.

5. Analysis and Preparation for the Cut

5.1 Face Shape Analysis

5.2 Texture and Density Analysis

Porosity test: Place a hair in a glass of water. If it floats → low porosity. If it sinks slowly → medium porosity. If it sinks immediately → high porosity.

5.3 Client Preparation

6. Safety and Hygiene Standards

6.1 Tool Disinfection

According to the National Infection Prevention Guidelines (Public Health Agency of Canada):

Contact time: Minimum 10 minutes in the disinfectant solution.

6.2 Hand Hygiene

6.3 Posture and Ergonomics

7. Calculations and Measurements in Cutting

7.1 Unit Conversions

Example: A cut requires a length of 1.5 inches. In cm: 1.5 × 2.54 = 3.81 cm.

7.2 Calculating Reduction Percentage

For a 20 cm cut to be reduced by 25%:

Reduction = 20 × 0.25 = 5 cm

Final length = 20 − 5 = 15 cm

7.3 Calculating the Cutting Angle with Inclined Shears

If the shears are inclined at Ω degrees relative to the section, the effective cutting angle is:

Effective angle = 90° − Ω

Example: Ω = 30° → Effective angle = 90° − 30° = 60°.

8. Pitfalls to Avoid

9. Tips for the Red Seal Exam

Summary

Hair cutting is a technical skill requiring mastery of:

Key formulas to remember:

Success on the Red Seal exam relies on an integrated understanding of these concepts. Don't just memorize: understand why each angle, each tension, each technique produces a specific result. This understanding will allow you to answer theoretical questions correctly and excel during the practical assessment.