Coloured scanning electron micrograph (SEM) of Cotton t-shirt collar with dirt, dead skin, etc. embedded in fibres. A T-shirt is a style of fabric shirt, named after the T shape of the body and sleeves. It is associated with short sleeves, a round neck line and no collar. T-shirts are generally made of cotton fibres knitted in a jersey stitch. They have a soft texture compared to woven shirts. The majority of modern t-shirts have a body made from a continuously woven tube so that the torso has no side seams. Magnification: x28 when shortest axis printed at 25 millimetres.