A size grading (pattern grading) is the process of systematically increasing and decreasing a base pattern to create a full range of sizes.
How Grading Works
Grading starts from a base size - usually a medium - and applies grade rules at key points on the pattern: bust, waist, hip, shoulder, armhole, sleeve length. Each point grows or shrinks by a set increment per size, so the pattern scales proportionally across the range.
Manual vs Computer Grading
Traditional hand grading uses a grading machine or manual shifting of pattern pieces - slow and skill-intensive. Modern CAD systems apply grade rules digitally in seconds and let graders visualize every size instantly. Most professional work is now done on computer, though the underlying principles are identical.
Common Grading Increments
- Bust/chest: typically 2 inches total circumference between sizes
- Waist: typically 2 inches between sizes
- Hip: typically 2 inches between sizes
- Length measurements: smaller increments, often 1/4 to 1/2 inch
FAQs
- What is a grade rule?
- A set of measurements defining how much each pattern point grows or shrinks between sizes.
- Who does the grading?
- A pattern grader, often using CAD software.
- Can grading be wrong?
- Yes - bad grade rules cause fit issues that compound across sizes.
Glossary: see the full fashion glossary for more apparel industry terms.