Full Bust Costume Fitting

The Full Bust Adjustment (FBA)

The FBA adds width at the bust apex of any bodice pattern without changing the shoulder, neckline, or waist. Measure the difference between your high bust and full bust — this is the amount to add. Slash the pattern at the apex and spread; retrue the dart. This is the single most important technique for full-bust fitting.

Dart Repositioning

After an FBA, reposition the bust dart to point at your actual apex rather than the pattern's assumed position. A dart that misses the apex creates drag lines and bunching.

Letting Out a Bought Costume

For bought costumes, open the side seams from armhole to waist, let out 1–1.5cm at the bust, tapering to the original seam at waist and underarm. This targeted approach avoids changing the rest of the fit.

Built-In Support

Boning channels, sewn-in cups, and shelf bra construction within the costume provide support without requiring a separate bra. This is the most reliable approach for strapless or fitted costume wear during long convention days.