Seam choice affects durability, appearance, comfort and cost. It is a specification worth making deliberately rather than leaving to the factory to assume.
Common seams
- Plain seam, the simplest, usually finished separately
- Overlocked seam, common in knits, which sews and finishes together
- Flatlocked seam, lying flat against the body
- French seam, enclosing raw edges, used in fine wovens
- Flat felled seam, strong and enclosed, used in workwear and denim
- Coverstitched hem, common on knit hems and cuffs
Operation count drives cost
A flat felled seam requires more operations than a plain seam and costs more accordingly. Specifying premium seams throughout a garment where they are not needed adds cost without adding perceived value.
Comfort against the skin
Flatlock seams reduce bulk and rubbing, which matters for close fitting garments and activewear. For loose garments the benefit is smaller and the cost may not be justified.
Durability at stress points
Reinforcement belongs where the garment takes load: armholes, crotch seams, pocket corners and closures. Bartacks and reinforced seams there are usually worth their cost.
Specify it or inherit it
If your tech pack does not specify seams, the factory will choose based on what is efficient on their machines. That may be exactly right, but it should be a decision you saw.