3. Seam in Garments
Seam types are the place where two pieces of fabric are joined by application of a
series of stitches or stitch types with a defined geometry. Over the years there are a
number of different types of seams that have been developed to do different jobs.
Many have largely been superseded by the development of machine stitches that
finish as you sew them, and by the development of the over locker (or serge in some
parts of the world), it is useful to know some of the basic seams types and finishes.
Seam in Garments
4. A seam is made when two or more layers of fabric are stitched together.
It’s the ‘line’ that is formed by sewing together pieces of cloth. Stitches
used to make such a line.
Seam
8. Superimposed Seam (SS): The superimposed seam is achieved by two or more
separate pieces of together. This is the one of the most common method of
seaming. The most basic superimposed seam is made when one ply of fabric is
stacked upon another with thread stitching through all plies of fabric. Variations are
plain seam, French seams and Double machine seam.
Lapped Seam (LS): Lapped seam is made with two or more pieces of fabric
overlapping each other. LS commonly, but not always, have one ply of fabric fold
under itself for a finished edge. Lapped seams are common when sewing side
seams on jeans and dress shirts. This class of seaming has the largest number of
variations.
Bound Seams (BS): Bound seam is made to finish and edge of a garment. A
common example of this would be a neckline of a Crew T. A bound seam is one
piece of fabric encompassing the raw edge of another piece of fabric. There are
many variations of a bound seam.
COMMON TYPES OF SEAMS
9. Flat Seam (FS): A flat seam is constructed by having two pieces of fabric meet
precisely at their edges. A cover stitch is used to sew the two pieces of fabric
together. This stitch has multiple needles and creates a stitch perpendicular to the
seam line. This creates a flat seam. Plain seam is a flat seam.
Edge Finished Seams (EF): This seam is used to prevent the edges of the fabric
from rolling or curling. Primarily used for knit fabrics and is suitable for straight or
curved seams and edges.
Ornamental Seam (OS): this seam is made using machines with zigzag capability. It
is used on a plain seam on woven or knit fabric. The zigzag stitch length (coverage)
must be adjusted to accommodate and prevent fabric from raveling. The more the
fabric ravels, the closer together the stitches need to be (tighter or shorter stitch
length).
COMMON TYPES OF SEAMS
10. Significance and Use
Selection of correct seam type for a particular assembly is very important as improper
selection of stitch type, seam type or thread type can result in failure of the sewn seam
and failure of the garment. The most important aspect of a properly constructed sewn
seam is strength, elasticity, durability, security and appearance. These characteristics
must be balanced with the properties of the material to be joined to form the optimum
sewn seam. The selection of the seam type and stitch type should be based upon these
considerations.
Strength: The seam efficiency of the sewn seam should be so that sewn seam strength
is balanced and can withstand the everyday usage of the garment.
Elasticity: Elasticity of sewn seam should be slightly greater than that of the material
which it joins. This will enable the material to support its shape of the forces
encountered for the intended end use of the sewn item. The elements effecting the
elasticity and strength of a sewn seam depends upon fabric type and strength, seam
type, stitch type, stitch density (SPI), thread tension, and thread strength and elasticity.
SIGNIFICANCE AND USE OF SEAM
11. Durability: Durability of a sewn seam depends largely upon its strength relative to the
elasticity of the seam and the elasticity of the material. For making durable sewn
seam, the thread size and stitch density must be carefully chosen to avoid puckering.
Security: Security of sewn seam depends chiefly upon the stitch type, SPI, and its
susceptibility to become unraveled. The stitch must be well set to the material to
prevent snagging that can cause rupture of the thread and unraveling of certain stitch
types.
Appearance: Appearance of a sewn seam generally is governed by the proper
relationship between the size and type of thread, the stitch density, and the texture
and weight of the fabric.
There are a number of different types of seams that have been developed over the
years to do different jobs. While many have largely been superseded by the
development of machine stitches that finish as you sew them, and by the development
of the over locker (or 'serge' in some parts of the world), it is useful to know some of
the basic seams types and finishes.
SIGNIFICANCE AND USE OF SEAM
12. A TABLE FOR DIFFERENT TYPES OF SEAM & THEIR EXAMPLE
13.
14. SUPERIMPOSED SEAM
Seam Class-1 : Superimposed seam
The superimposed seam is used to join two or more pieces of material (fabric or
otherwise) together. It is created by one ply of fabric being stacked (superimposed)
upon another with their right sides (the one that will show when the item is worn or
used) together and using thread to stitch through all layers. This is one of the most
common and simplest methods of seaming and is used to construct most commercial
garments.
Usage:
1. Side seam of basic pants.
2. Side seam of shirts.
15. Usage:
1. Inner seam of long sleeve.
2. Side seam of jeans etc.
Seam Class-2 : Lapped seam
This class of seaming has the largest number of variations. This type of seam is
produced by overlapping of two raw edges of the fabric and at least one of the edge
must be neatened in a decorative manner, by using two or more rows of zigzag
stitching.
LAPPED SEAM
16. Seam Class-3 : Bound seam
The purpose of a bound seam is to finished the raw edge of a garment. A common
usage of this finish is seen on the neckline of a collarless garment made of woven
fabric. A bound seam is made by using one piece of usually bias-cut fabric to enclose
the raw edge of another piece of fabric. There are many variations of a bound seam.
Technically this is a finishing method, rather than a seam.
Usage:
1. To attach elastic in the edge of garments.
2. In Neck edge of basic T-shirt, waist band, woman’s blouse, baby’s
nightgown, child bishop dress, camisole etc.
BOUND SEAM
17. Seam Class-4 : Flat seam
In this seam type, fabric edges buttled together without causing any gap and joining
across by a stitch, which has two needles sewing into each fabric ancovering threads
passing back and forth between these needles on both sides of the fabric.
Usage:
1. Hem of knitted underwear.
2. For decorative garments items.
FLAT SEAM
18. Seam Class-5 : Decorative seam
The seam in this class is produced by decorative stitching across a garment panel,
where single or multiple rows of stitches are sewn through one or more layers of
fabric. These several layers can be folds of the same fabric.
Usage:
1. To produce gathering on fabric.
2. To make pleat in the garments.
3. To attach ribbon etc.
DECORATIVE SEAM
19. Seam Class-6 : Edge neatening seam
Seam types in this class include those, where fabric edges are neatened by means
of stitches (over lock stitches) well as folded hems and edges.
Usage:
1. In side edges of a pant’s side seam.
2. Hems of skirt, shirt etc.
3. Button holes.
EDGE NEATENING SEAM
20. Seam Class-7 : Like as lapped seam
When additional part such as elastic , lace etc are attached to the fabric then Seam
Class-7 is used. Seam in this class relate to the addition of separate items to the
edges of a garment part. They are similar to the lapped seam, except that the added
component has a definite edge on both sides.
Usage:
1. Inserted elastic on the leg of a swimming dress.
2. Band and lace attachment to the lower edge of sleeve.
3. Elastic braid on the edge of the bra.
LIKE AS LAPPED SEAM
21. Class 8:
Final seam class, where only one piece of material need to be involved in constructing
the seam.
Usage:
1. Belt loop as used on jeans, rain coat.
2. Loop for braid penetration in children wear.
CLASS 8
22. 1. Smooth and even in appearance on the inside and outside. (Properly
adjust machine tension, stitch length, and presser foot pressure to suit
the fabric and thread. Fabric should not pucker)
2. Even in width through out
3. Pressed open or closed according to the type of seam and how it is used
in the construction process
4. When stitched with thread, the thread should be appropriate to the fabric
type and fiber content. Thread color should match or slightly darkest.
5. Neat and smooth in appearance, without added bulk.
6. Free from raveling, stretching, rolling and curling.
7. Should not be visible from right side of garment.
SEAM - BEST PRACTICES
23. Factors affecting appearance of Seam
The technique and skill of the sewing machine operators also govern the
appearance of sewn seams. Some of the factors that will adversely affect the
appearance of a seam
Stitch Defects Seam Appearance Defect
Loose Stitches Puckers
Poorly formed stitches Twists
Crowded stitches Plaits
Tight stitches Undulations
Crooked stitches Run-off (raised seams)
Skipped stitches Raw edges exposed (felled seams)
FACTORS AFFECTING APPEARANCE OF SEAM
