IGMT- 1 Module III SEAM TYPES

Introduction to Seam Types

  • A seam is a joint between two pieces of fabric created by applying stitches or stitch types to material layers.

Types of Seams

  • The British Standard categorizes stitched seams into eight classes based on the number of components:

    • CLASS 1: Superimposed seam

    • CLASS 2: Lapped seam

    • CLASS 3: Bound seam

    • CLASS 4: Flat seam

    • CLASS 5: Decorative stitch

    • CLASS 6: Edge neatening

    • CLASS 7: Seam with an added separate component

    • CLASS 8: Belt loop attachment

CLASS 1: Superimposed Seam

  • Formed by superimposing edges of one fabric onto another. Options for stitches include lockstitch, chain stitch, etc.

  • Subclasses: SSa (side seams), SSb (finishing belt ends), and others.

  • Types: French seam (encloses seam allowance) and Piped seam (fabric-covered cord).

CLASS 2: Lapped Seam

  • Created by lapping two fabric pieces; not common in clothing due to raw edge issues.

  • Uses lockstitch or chain stitch; typically seen in durable applications like sails and leather garments.

CLASS 3: Bound Seam

  • An edge of fabric is bound by another piece fabric to finish raw edges.

  • Uses lockstitch or cover stitch. Common in necklines and shirt hems.

CLASS 4: Flat Seam

  • Fabric edges are butted together without overlap, often used in knit fabrics for a bulk-free appearance.

CLASS 5: Decorative Stitch

  • Primarily for decorative sewing on garments with varied stitch techniques to create patterns.

CLASS 6: Edge Neatening

  • Seams that neaten fabric edges, including hems and folded edges.

CLASS 7: Seam with Added Component

  • Relates to adding items (e.g., lace, elastic) to garment edges.

CLASS 8: Belt Loop Attachment

  • Involves belt loop connectors on garments like jeans; can be done quickly with special machinery.

Considerations for Selecting Seam Type

  • Strength: Must withstand daily usage, influenced by thread type, stitch type, needle size, etc.

  • Elasticity and Flexibility: Should be slightly greater than the base fabric.

  • Durability: Relies on the seam's strength and elasticity.

  • Security: Stitches must prevent unraveling.

  • Appearance: Affected by thread size, stitch density, and fabric texture.