What a reinforcement in a seam consists of
Short answer: A reinforcement is either extra stitches, a narrow tape or an extra layer of fabric placed in the seam. Its purpose is to spread the pull over more threads, so a single thread does not carry the whole load alone.
The purpose is to spread the pull
A seam holds because the threads carry the load together. If too few threads carry too much, they break first. A reinforcement therefore does not simply make the seam thicker, it spreads the pull over more threads or more layers, so the strain does not gather in one spot of the garment.
Extra stitches
The simplest reinforcement is an extra row of stitches on top of the first. That doubles the number of threads carrying the load on the same stretch. The method is simple and adds little bulk, which is why it is used where there is no room for anything thicker or where the fabric should stay soft.
An inserted tape
A narrow woven tape is laid into the shoulder seam or the neck. The tape stretches less than the fabric and therefore holds the shape of the garment. It works like a firm line in a seam that would otherwise follow the fabric outward, and that is the point: to set a limit on how far the fabric can give.
Why a tape stretches less
A woven tape has threads that lie straight, while knitwear is built from loops that can straighten out. That is why the tape hardly gives when pulled. Sewn into a seam, it holds the fabric in length. See bamboo sweatshirts for men and feel whether a tape sits in the shoulder seam.
Extra fabric
A triangle or gusset is sewn in where several seams meet. That moves the crossing and gives the fabric room to move. Instead of several seams meeting at one point, the meeting is spread out, and there is no single spot where all the strain gathers when you stretch or sit.
Where they typically sit
Reinforcements sit at the neck, in the shoulder, at pocket edges and in the crotch. These are places where the fabric either carries the weight of the garment or where several seams meet. If you know the places, you know where to look when you want to judge how well something is made. See bamboo undershirts for men and bamboo footies for men.
Can you see the reinforcement from outside
Sometimes. Turn the garment inside out and you will see the tape or the extra row of stitches. On the right side a reinforcement can be completely hidden, and that is often the intention, because it should do its job without adding to the look. If you have never looked, watch for a firm strip or a double row of stitches.
Does a reinforcement make the garment stiff
A little at the spot, but it sits where the fabric should not stretch anyway. The shoulder should hold the garment up and not stretch with every movement. Elsewhere the fabric stays soft and elastic, so the overall feel does not change even though there is a reinforcement in the seam.
What to look for
To judge a seam, turn the garment inside out and check whether there are extra stitches, a tape or a gusset where several seams meet. If the seams lie evenly and the ends are locked, that is a good sign. A reinforcement shows that someone thought about where the garment is stressed most.
Frequently asked questions
Can I see the reinforcement from outside?
Sometimes. Turn the garment inside out and you will see the tape or the extra row of stitches. On the right side it can be completely hidden, and that is often the intention.
Does a reinforcement make the garment stiff?
A little at the spot, but it sits where the fabric should not stretch anyway. The rest of the garment stays soft and elastic, so the whole does not change.
Where do they typically sit?
At the neck, in the shoulder, at pocket edges and in the crotch. These are places where the fabric carries weight or where several seams meet at the same point.
You can find the full range at Bamboo-Clothing.com.
