The leg hems on our trunks flip up and roll during wear. What should we change?
Hems flip up when a jersey edge curls, the hem is too narrow or tight, or the leg pattern pulls. A banded or elasticated leg, a wider hem or a different fabric usually fixes it.
Customers say the cover-stitched leg hems on our cotton-spandex trunks roll up toward the hips after a few hours. Some also say the hem flipped after washing. What should we change for the next order?
Main answer
Leg hems on trunks flip up for a few common reasons. Single jersey fabrics naturally curl at cut edges, and a narrow turned hem may not be enough to hold the edge flat. If the hem is sewn with tension, or the cover stitch does not stretch with the fabric, the edge can pull and roll. The leg pattern also matters: if the leg opening is too tight or angled so it rides up, the hem is pulled upward with each step.
Check the fabric first
Look at a cut edge of the fabric. If it curls strongly, the hem has more work to do. Fabrics with more elastane or a different knit, such as interlock or a firmer jersey, curl less. Also check whether the fabric twists after washing, which can make hems turn. Bow, skew and spirality can be checked with methods such as ASTM D3882 and on washed garments.
Hem construction options
Common alternatives to a simple turned hem are a self-fabric leg band, a covered elastic leg, a wider double-turned hem, or a bonded or laser-cut edge on synthetic fabrics. A leg band or soft elastic gives the hem structure and some grip, which usually stops rolling, but it also changes how the leg feels, so check comfort. Ask the factory which options its machines support and sample two or three.
Stitch and tension
The cover stitch needs to stretch with the leg. If the stitch is too tight or the stitch density is wrong, the hem can pucker and pull. Ask the factory to show the hem stretched by hand, and check that the stitches do not crack and the hem recovers flat.
Pattern and fit
If the leg is short and the opening tight, trunks tend to ride up regardless of hem. Fit samples on people in several sizes, walking and sitting, and compare leg length and opening with your specification.
Test after washing
Wash samples with a named procedure such as ISO 6330 at your label settings and check the hems again. Fabric stretch and recovery can be compared with a method such as ASTM D2594.
Write the chosen hem or band construction, widths, stitch type and leg opening per size into the specification, and approve a washed sample before bulk.
Sources and further reading
- ASTM D2594 — Stretch Properties of Knitted Fabrics Having Low Power
- ISO 6330:2021 — Domestic washing and drying procedures for textile testing
- ASTM D3882 — Bow and Skew in Woven and Knitted Fabrics
Standards and rules are summarised from their published scope or official guidance. Use the current edition and confirm requirements for your market.
Three perspectives on this question
Purchasing perspective
A leg band adds a cutting and sewing step, so I'd ask for the price difference for each hem option.
Merchandising perspective
Customers notice rolling legs immediately. I'd test options with people wearing them all day before choosing.
QC perspective
We'd check hems on washed bulk samples in every size and stretch them by hand to look for cracked stitches.
Working on a similar program?Send your tech pack, fabric references and test requirements. We reply with a quote and the questions we need answered.
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