What Makes a Hem Hold Its Shape
By The Velocity Wear Team
A hem holds its shape when three things line up: enough folded fabric to give it body, a stitch that can stretch with the cloth without snapping, and a fabric that was properly relaxed before it was cut. Get any one of those wrong and you get the familiar failures, a curling tee hem, a rippled wave along a sleeve, or a row of popped stitches after the first proper stretch.
What a Hem Is Actually Doing
A hem is not decoration. It is a solution to a problem, namely that a cut edge of fabric is unstable. Woven fabric frays at a raw edge. Knitted fabric does something worse: single jersey curls, because the loop structure is unbalanced and the fabric relieves that imbalance by rolling towards one face. Every plain tee hem in existence is fighting that tendency.
Folding the edge under does two useful things. It puts a doubled or tripled layer of fabric at the edge, which is heavier and therefore hangs straighter, and it hides the unstable cut edge inside the fold where it cannot curl.
Twin Needle and Coverstitch
Look at the bottom of almost any tee and you will see two parallel rows of stitching. That is a twin needle hem, and the parallel rows are not two separate operations; they come from a single machine with two needles sharing a bobbin thread that zigzags underneath. That underside zigzag is the important part, because it is what allows the seam to stretch. A single straight row of lockstitch on a jersey hem will snap the moment someone pulls the garment over their head.
Coverstitch is the same idea done more thoroughly, with a chain of thread covering the underside of the hem. It is stronger, it lies flatter against the skin and it is standard on better sweatshirts and performance garments. If you can turn a garment inside out and see a neat covered chain rather than a loose zigzag, you are looking at a better finish.
Depth, and Why Cheap Hems Look Thin
Hem depth is how much fabric is folded up before stitching. A deeper hem costs slightly more fabric on every single garment, which is why it is one of the first places cost gets taken out of a blank. The visual difference is immediate: a shallow hem gives a flimsy, floppy edge that flutters, while a generous one gives a defined line that hangs straight.
You can feel it in a second. Roll the hem between finger and thumb. There should be a distinct thickness with body to it, not a papery double layer. On a hoodie the same logic applies to the sleeve hems even when the waist has a rib, because those sleeve hems are what people see when the cuffs are pushed up.
- Turn the garment inside out and look at the hem stitching: a covered chain is better than a bare zigzag, and a single straight line on a knit is a warning sign.
- Pull the hem sideways with reasonable force and let go. It should return without leaving a stretched ripple.
- Roll the hem between your fingers to judge depth; a shallow, papery hem will flutter and curl in wear.
- Check the point where the hem crosses the side seam, since that junction is thickest and is where skipped stitches usually appear.
- Wash the sample before you judge anything, because most hem problems are invisible until the fabric has relaxed once.
Why Hems Go Wavy
A rippled, lettuce-edge hem after washing is one of the most common complaints and it is almost never a stitching fault. It happens when the fabric was fed through the hemming machine under tension and then relaxed later in the wash. The stitching holds its length while the fabric around it shrinks back, so the excess fabric has nowhere to go but out of plane.
The fix happens upstream, in how the fabric is relaxed and how the machine is set, so it is a supplier quality question rather than something you can specify around. A hem that is going to wave usually reveals itself on the first or second wash.
“"Judge a hem after it has been washed. Before that you are just admiring how well the factory pressed it."”
Raw Edge and Deliberately Unfinished Hems
Some garments use a raw, unhemmed edge as a design choice, common on heavyweight cropped pieces and certain streetwear cuts. On a stable, heavy loopback fabric this can work and can stay looking intentional for a long time. On light single jersey it will curl into a rope within a few washes, and what looked deliberate starts looking like a fault.
If you are ordering raw-edge pieces, be honest with yourself about what your customer or your staff will think in three months. The look ages very differently depending on fabric weight and structure.
Hems and Print Placement
One practical point for anyone positioning artwork. Never use the hem as your measuring reference for a front or back print. Hem position is the measurement that varies most between sizes and moves most after washing, so a design measured up from the hem drifts on the body across a size run. Measure down from the shoulder seam instead and the placement stays consistent.
Velocity Wear supplies online from a 20-piece minimum per order with sizes mixed freely, so ordering a small trial run and washing it before committing to a larger rollout is straightforward. The free Design Studio shows how artwork sits on the garment, the instant price calculator gives live pricing as you change garment, method and quantity, and tracked UK delivery is typically 2 to 5 working days after dispatch.