Two parallel seams on the hoodie, what they are

Short answer: Two parallel seams on a hoodie are a double row of stitching, often made with two needles, that looks neat on the outside and gives with the fabric. The seam is elastic and strong, so it follows your movements without coming apart.

What you see on the outside

Look at the edge of a hoodie, at the cuff, the waistband or the hem, and you often see two parallel lines of thread. They form a double row of stitching and hold a folded edge in place. It looks tidy, and it is a classic detail in sweat fabric that you will recognise on many sweaters.

What happens on the inside

On the inside the thread lies differently. It often forms a row of interlocking loops that give the seam an elastic structure. That is why the seam can stretch along with the fabric. Turn the hoodie inside out and look. A flat, even seam on the inside usually means it lies calmly against the skin.

Why it is elastic

Sweat fabric is knitted and gives when you move. An ordinary straight seam is stiff and can split if the fabric is pulled. The double stitching is made to give, so it stays put when you raise your arms or pull the sweater on. That is the main reason it is used at the sleeves and hem.

Where the seam usually sits

You find the seam where the fabric is folded in and the edge has to hold its shape: at the neckline, at the hem, at the cuff and sometimes along the pocket. Run a finger along the edge and feel the two lines. If they run parallel without the fabric puckering, that is a good sign.

What a proper seam looks like

Check that the two lines are straight and the same distance apart, and that the fabric lies flat without waves. If the fabric draws together, the thread was too tight. If a thread runs, you should mend it quickly before the seam opens. Also check that the ends are secured, especially at the hem of the hoodie and at the cuffs.

Fit and pressure

Because the seam sits in the edge, it can be felt at the wrist and waist if it is stiff or wide. Try the sweater on, move around and see whether the seam presses. An elastic double stitch should not hurt. If the sweater fits well you can wear it all day, also together with a bamboo jogging set for men.

Washing and wear

Seams wear through heat and friction. Wash the hoodie inside out at a low temperature and avoid a hot tumble dryer, which can weaken the thread. Hang it up or lay it flat so the seam keeps its shape. Check the seams now and then, so you can mend a loose stitch before it grows.

The same seam on several sweaters

The double stitching appears on many sweat garments. Look at the edges of a bamboo sweatshirt for men and you will find the same lines at the neck and hem. If you want to see the whole selection, look at the range for men and compare the seams before you choose.

Frequently asked questions

Are two parallel seams stronger than one?

Often yes, because they hold the edge flat and give the fabric more support. More important is that the seam is elastic, so it gives with the fabric.

Why does the seam look different outside and inside?

Because the thread from two needles gathers on the inside in a row of loops. That makes an elastic seam that can stretch when you move.

What do I do if one of the lines comes undone?

Do not cut the thread. Sew it back by hand, or have a seamstress secure it, so the rest of the seam holds.

You can find the full range at Copenhagen Bamboo.