Seam (sewing)

In sewing, a seam is the join where two or more layers of fabric, leather, or other materials are held together with stitches. Prior to the invention of the sewing machine, all sewing was done by hand. Seams in modern mass-produced household textiles, sporting goods, and ready-to-wear clothing are sewn by computerized machines, while home shoemaking, dressmaking, quilting, crafts, haute couture and tailoring may use a combination of hand and machine sewing.

In clothing construction, seams are classified by their type (plain, lapped, abutted, or French seams) and position in the finished garment (center back seam, inseam, side seam). Seams are finished with a variety of techniques to prevent raveling of raw fabric edges and to neaten the inside of garments.

All basics seams used in clothing construction are variants on four basic types of seams:

A plain seam is the most common type of machine-sewn seam. It joins two pieces of fabric together face-to-face by sewing through both pieces, leaving a seam allowance with raw edges inside the work. The seam allowance usually requires some sort of seam finish to prevent raveling.

Either piping or cording may be inserted into a plain seam.

In a French seam, the raw edges of the fabric are fully enclosed for a neat finish. The seam is first sewn with wrong sides together, then the seam allowances are trimmed and pressed. A second seam is sewn with right sides together, enclosing the raw edges of the original seam.

In a flat or abutted seam, two pieces of fabric are joined edge-to edge with no overlap and sewn with hand or machine stitching that encloses the raw edges. Antique or old German seam is the 19th century name for a hand-sewn flat seam that joins two pieces of fabric at their selvages. This type of construction is found in traditional linen garments such as shirts and chemises, and in hand-made sheets pieced from narrow loom widths of linen.

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