Why Seam Finishing Matters
An unfinished seam allowance will fray with wear and washing. Over time, the fraying works back toward the stitching line, weakening the seam. A finished seam allowance prevents fraying, creates a professional interior appearance, and extends the garment's life significantly. For costumes that will be worn multiple times, finishing seams is not optional.
Serging (Overlocking)
The fastest and most common professional seam finish — a serger trims the seam allowance and wraps the edge in thread simultaneously in a single pass. Serged seams are used in essentially all commercially produced garments. If you have access to a serger, it produces the most efficient seam finish for most costume construction applications.
French Seam
Encloses the raw edge within the seam itself — no exposed raw edges on either side. Process: sew wrong sides together first with a narrow seam allowance; trim; press; fold right sides together and sew the final seam enclosing the raw edges. Best for light to medium-weight woven fabrics where the seam won't be under heavy stress. Produces a beautiful interior finish.
Hong Kong Finish
Binds each seam allowance edge with a strip of bias-cut fabric. More time-consuming than serging but adds a couture quality to the interior. Best for non-stretch wovens where the added bulk of the bias binding won't cause problems. Appropriate for tailored pieces, historical garments, and corsets.