Pattern Cutting
Pattern Cutting
This domain tests how flat patterns are made, altered and prepared for fabric. Expect questions on blocks, grainlines, darts, seam allowance, notches, grading and fitting. Accuracy in preparation saves fabric and prevents fitting faults.
Core rules
- A block (sloper) is a close-fitting template with no seam allowance. Working patterns add seam allowance (often 1 cm, 1.5 cm at hems) and allowances for ease.
- Grainline must run parallel to the warp (selvedge) unless bias is intended; it affects hang and stability.
- Darts shape flat fabric to the body; they can be moved but not removed without adding fullness.
- Notches match seams; balance marks and drill holes transfer details. Grading increases or decreases a pattern by size rules.
- True bias (45°) stretches and drapes; use it deliberately for cowls or bias binding.
- Pattern pieces are labelled with name, size, cut quantity and grain.
Worked example
A bodice block is too tight at the bust. Adding only to the side seam distorts the armhole and grain. Instead, split at the bust point and add a dart intake or slash-and-spread; check ease, seam allowance and adjacent panels. Record the change on the pattern and true the seam lines.
Traps
Forgetting seam allowance on a block; placing grainline on the fold incorrectly; clipping notches too deep; altering one seam without checking adjacent pieces.