Pattern Making and Grading
What the exam tests
Pattern tools, body measurement, drafting of blocks, seam allowance, grainline and notches, and the grading of a pattern from one size to another. Expect short drafting or grading calculations and identification of pattern symbols.
Core rules
- A block is a close-fitting master pattern without style details; a working pattern includes seam allowance, hems and facings.
- Ease is the difference between body measurement and garment measurement; without it, woven garments cannot move.
- Grainline is marked parallel to the centre front/back; cutting off-grain causes twisting.
- Notches match seams; balance marks and drill holes transfer darts and pockets.
- Grading increases or decreases a pattern by grade rules at grade points. Bust is commonly graded 2 inches per size in women’s wear; the front bodice half pattern represents a quarter of the body, so its bust width grows by 0.5 inch per size.
Worked example
A size 10 front bodice is being graded to size 12. The full bust grade is 2 inches. The front bodice half pattern is one quarter of the bust circumference, so the width increase is 2 ÷ 4 = 0.5 inch. If the grade rule adds 0.25 inch at the side seam, the remaining 0.25 inch is placed at the armhole grade point; the centre front stays as the fixed reference line. Reasoning: grading must preserve balance and the centre front, not simply widen one edge.
Traps
- Adding seam allowance to a block and then forgetting it on the working pattern.
- Grading from the centre front instead of moving grade points.
- Ignoring ease when comparing pattern width with body measurement.