This document defines and classifies different types of seams and stitching used in garment construction. It discusses four seam classes (superimposed, lapped, bound, and flat seams), with various types listed under each class. It also covers two classes of stitching - edge finishing and ornamental. Key factors that determine seam appearance and performance such as drapability, consistency, flatness, elasticity, strength and abrasion resistance are outlined.

1. SEAM CLASSIFICATION

2. What is Seam ???
A seam is a joint consisting of a
sequence of stitches uniting two or
more pieces of material(s) and is used
for assembling parts in the production
of sewn items.
Joint = stitches + 2 or more pcs. of material

3. Seam Classes
As per Federal Government Standard 751a
Four Seam Classes-
 Superimposed Seam
 Lapped Seam
 Bound Seam
 Flat Seam
Two Stitching Classes-
 Edge Finishing
 Ornamental Stitching

4. Superimposed Seam
The superimposed seam (SS)
class is formed by joining two or
more pieces of fabric, usually
with seam allowance edges even
and one piece superimposed
over the second.

5. Superimposed Seam Types

6. Waistband -
inside
Waistband -
outside

7. Stitching thread

8. Superimposed Seam Types
SSd-Not common.
SSe- Runstitch & Topstitch- For making collars & cuffs on
shirts; attaching front pockets, bagging front pockets,
setting fly on chinos, etc.

9. Superimposed Seam Types
SSd-Not common.
SSe- Runstitch & Topstitch- For making collars & cuffs on
shirts; attaching front pockets, bagging front pockets,
setting fly on chinos, etc.
SSf-Butt Seam & Tape- For butt seaming & taping heel
seams on shoes, etc.
SSh- Seaming & Cover seaming- For cover seaming knit
tops, undergarments to reinforce seam and give it a
decorative appearance.

10. Superimposed Seam Types
SSj-For attaching a zipper tape between shell and facing.
SSk- Seam with Piping-For seam apparel, furniture with
piping in seam.
SSl- For setting front pockets on jeans.
SSn- Hem Seam- For seaming fabrics that may be
susceptible to seam slippage.

11. Superimposed Seam Types
SSp- Hem Seam - For seaming fabrics that may be
susceptible to seam slippage.
SSq- Seam, Fold & Cord-For attaching yokes to back or
shoulder joining on shirts, blouses, etc. Similar to LSe
but done in 2 steps.
SSs-Hemming and attaching zipper tape.

12. Superimposed Seam Types
SSt- For seaming knitted or woven elastic to boxers and gym
shorts.
SSv-Not common.
SSw- Mock Felled Seam - For side seaming shirts, blouses,
dresses, etc.

13. Lapped Seam
The lapped seam (LS) class is
defined as two or more pieces of
fabric joined by overlapping at
the needle.

14. Lapped Seam Types
LSa- Lap seaming- Attaching knitted cuffs – generally sewn
with a coverstitch - 605 or 607.
LSb- Not as common as LSq where piece is attached and
then corded or topstitched. My T-shirt!!
LSc- Felled Seam - Seaming jeans, shirts, jackets, etc.
Generally, with a two or three needle 401 Chain stitch.
LSd- Patch Pocket Setting - For setting patch pockets,
flaps, pocket facings, etc., generally, with a 301
Lockstitch.

15. Lapped Seam Types
SSe- Yoking - Seaming yokes to back on shirts or blouses in
one operation. Not as common as SSq.
SSf- Yoking-Seaming yokes to back on shirts or blouses in
one operation.
SSg-Two Piece Waistband-Attaching a waistband to chinos
or work pants.
SSj-Two Piece Waistband-Attaching a waistband to chinos
or work pants.
Fusing, interlining

16. Lapped Seam Types
LSk- Waist banding on pajamas; making rod pocket on
curtains & shower curtains, etc.
LSl- Joining bib to pants of bib overall in 1 operation.
LSm-Set- On Center Plait- Attaching set-on center
plaits to shirts and blouses.
LSn- Not common.

17. Lapped Seam Types
LSq- Seam & Cord Seam- Side seam on jeans; chinos;
jackets, etc.
LSr- Sleeve Set- Setting sleeves on dress shirts or
blouses.
LSs-Patch Pocket Setting- For setting large patch
pockets on suit coats, overcoats, and jackets.
LSz-Joining & Taping- Joining & taping fronts of knit
briefs & thermal underwear.

18. Bound Seam
The bound seam (BS) Class requires
a separate piece of fabric that
encompasses the edge of one or
more pieces of the garment.

19. Bound Seam Types
BSa- Binding carpets, etc, with selvedge
edge binding.
BSb- Setting collarettes on tee shirts; binding legs and fly
on knit briefs, etc. Usually sewn with a 406 bottom cover
stitch.
BSc- Waist banding on Jeans-For setting sleeve facings
to shirts, piping edges of outerwear, etc. Can be sewn
with a 301 lockstitch or 401 Chain stitch.
BSd- Seaming with selvedge edge binding on
outerwear.

20. Bound Seam Types
BSe- Seaming and binding on outerwear.
BSj- Sewn in 2 operations - Mock clean, finish binding.
BSg- Sewn in 2 operations - Mock clean, finish binding.

21. Flat Seam
The flat seam (FS) class is the
smallest class. The formation of
this seam occurs with the butting
together of two pieces of fabric, but
not overlapping them.

22. Flat Seam Types
FSa- Flat seaming - Flat seaming underwear,
fleece, exercise wear, etc. Generally, sewn with
a 607 stitch. Sometimes a 606 Flatlock Stitch.
Fsf- Bolt-end seaming with a 501 Stitch.

23. Stitching Classes
In this class the stitching is performed
on a single piece of fabric. The fabric
may be folded in variety of ways so the
stitching may be through more than
one thickness

24. Stitching Classes
Two Stitching Classes-
Edge Finishing
Ornamental Stitching

25. Edge Finishing
Edge finishing (EF) is stitching that
encompasses the cut edge or provides a
finish for a single ply of fabric with a
folded edge configuration.

26. Edge Finishing Types
EFa- Hemming selvedge edge, shirtfront.
EFb-Clean Finish Hem-Hemming shirts, jeans, shorts,
etc.
EFc- Blindhemming-Hemming bottoms of tee
shirts, undershirts, etc. usually sewn with a 503
Stitch.
EFd- Serging- Serging pants panels, fly facings, etc.

27. Edge Finishing Types
EFe- Serge & Hem-Serging edges of napkins,
sheer curtains, etc.
EFf- Hem & Insert- Hem and insert elastic to
infant panties, etc.
EFg-Hem and insert elastic to infant panties,
etc.
EFh- Belt loops- Making belt loops for
jeans and casual pants, shorts, etc.
usually sewn with 406 stitch.

28. Edge Finishing Types
EFj- Making straps or belts with clean finish.
EFl- Blindstitch Hem- Hemming dresses, slacks,
coats,and bedspreads. Generally, sewn with 103
blindstitch.
EFm- Blindstitch Hem- Hemming Dresses, slacks,
coats, and bedspreads. Generally, sewn with 103
blindstitch.
EFn- Making straps or belts with clean finish.

29. Edge Finishing Types
EFp- Making straps or belts with clean finish.
EFq-Hem and insert elastic to infant panties, etc.
EFr-Tunneled elastic- Hem and insert elastic to
infant panties, etc.
EFu- Making Spaghetti- Making straps. Stitch is
hidden and not visible.

30. Edge Finishing Types
EFv- Centerplaiting- Cut-on centerplait. Generally,
sewn with 2 rows of 401 stitch.
EFy- Making straps or belts with clean finish.
EFz- Making straps or belts with clean finish.

31. Ornamental Stitching
Ornamental stitching may be used on a single ply
for decorative purposes. It can be done anywhere
except the edge.

32. Ornamental Stitching Types
OSa- Decorative Stitching-Decorative stitch
back pockets on jeans; saddle stitching.
OSf- Sewing Darts- Dart panel on slacks,
chinos, blouses, etc.

33. Seam Appearance
Is evaluated on the following factors:
Drapability- is affected by the flexibility of
materials and seam construction. Seams
need the same amount of drapability as the
rest of the garment. Use of heavy thread,
complex seam structures mainly contribute
to the rigidity of a seam.

34. Seam Appearance
Consistency of stitch & seam formation-
very critical to garment appearance as
irregularity affects the shape of the
garment and can cause poor fit and
unsightly appearance.

35. Seam Appearance
Seam Flatness- A flat seam is free of fabric
creases, waviness and pucker. Some factors
affecting seam flatness may be controlled
by pressing, top stitching and cover
stitching.

36. Seam Performance
Relates to the elasticity, strength and
flexibility of a seam.
Elasticity- Involves two factors-elongation
and recovery.
Seam elasticity is the degree that a seam
recovers to its original length immediately
after elongation.

37. Seam Performance
Elongation is the amount that a seam can be
stretched without breaking.
Recovery is the return of its original length
when the stress is removed.

38. Seam Performance
Strength- is important factor in determining the
durability of a garment and determined by the
pulling force & abrasion
Seam Tenacity is the force necessary to break the
fabric or the weakest stitch of a seam

39. Seam Performance
Seam abrasion resistance is the amount of rubbing
action needed to wear away stitches in the seam
Seam strength is related to stitch type, thread
strength & tension, seam type & width and spi