Pattern Drafting and Adaptation
Drafting a basic block
Pattern Drafting and Adaptation tests whether you can turn measurements into a flat pattern with correct grain, balance and seam allowance.
- Draft on paper with the centre front and centre back on a fold.
- Bodice rectangle width = (bust + ease) ÷ 2; depth = back length.
- Mark neck, shoulder slope, armhole curve, bust point and waist darts.
- Add seam allowance after drafting: 1–1.5 cm at seams, 2–3 cm at hems.
- Mark grainline, notches, fold line and dart legs.
Adaptation methods
- Slash and spread: cut the pattern and open it to add flare.
- Pivot: move a dart to a new position without changing fit.
- Dart conversion: turn a waist dart into gathers, a yoke or a princess seam.
- True the seams and keep the grainline parallel to the centre front.
Worked example
Bust 92 cm, waist 76 cm, ease 8 cm. Garment bust = 100 cm, half = 50 cm. Garment waist = 84 cm, half = 42 cm. Difference on the half block = 8 cm. Distribute 3 cm to the side seam, 2 cm to the back dart and 3 cm to the front dart; total = 8 cm. Draft darts about 12–14 cm long, ending before the bust point.
Traps
Forgetting ease; drafting with a body measurement only; a grainline that is not parallel to the centre; adding seam allowance twice; darts that are too short or too long; not truing armhole and side seams.