How to identify a T-shirt

What determines a T-shirt is the shape, not just the fabric.

There is a big difference between a good T-shirt and a bad T-shirt.

Where the red line is drawn. This is the lining of the shoulder on the inside of the T-shirt. One of its functions is to protect the neckline from deformation, and the other is to make it more consistent with the shoulder / bust line. The feature of this design is that it can make the boys with narrow shoulders and not big chest girth, which is more suitable for them. In other words, its shape will be more suitable for thin boys. It's not easy for strong boys to show their physical superiority. Like this one below

The other kind of shoulder lining has a higher position and a more straight line. The advantage of this design is to make the shoulders of boys look wider and make the average boys look stronger.

Next is the shoulder line. The shoulder line is the stitching of the body part and sleeve part of the T-shirt. If the thread falls right on your shoulder blades, the T-shirt is at least roughly fitted

The other is the sleeve length and cuff tightness of the T-shirt. In general, if the sleeves are shorter and the cuffs are tighter, your arms will look stronger, your arms will look longer, and your shoulders will be wider. 

The position of the hem of the T-shirt should cover more than the belt of the boy. If the boy's back is not too strong, it will appear too strong

The reason why the pattern is more important than the fabric is that no matter how good the fabric is, it can be bought with money. However, the pattern is the cumulative result of a brand in product design and user body data research. A good version with good fabric can make a common T-shirt become outstanding texture.