T-shirts refer to short-sleeved shirts of a simple four-piece design with a front, two single-piece sleeves and a back. In most cases they lack a collar and have knit finishing at the neck. T-shirts are typically made from knit fabrics, which makes them elastic, and they originated as undershirts but are now used as casual outwear. The "cut" or fit of the shirt, whether slim or normal, refers to how closely it follows the contour of the body.
Sizing and fit
Despite attempts for standardisation, clothing manufacturers generally follow their own rules for sizing and fit. Typical T-shirt sizes like small, medium and large are used as relative measurements in respect to each other, making no size or cut a universal description of clothes in that category. Furthermore, different companies use different fit models who reflect the target demographic of the clothing line. Sportswear brands will use an individual with a high level of fitness whereas a brand targeting teenagers will base their cut on the build of the average teenage boy. Manufacturers also take into account the current fashions and local tastes.
Sizing on a slim fit
Slim-fit shirts assume a wedge-shaped body type and typically include a 5 to 7.5 cm (2 to 3 inch) clearance at the waistline. They sometimes are cut so the shoulder seam or "yoke" of the shirt extends past the shoulders and onto the upper arm. As sizing is arbitrary, the sliminess of the cut may simply refer to how slim a fit is in respect to other shirts manufactured in that clothing line or for that brand.
Sizing on a normal fit
Normal-fit T-shirts assume a box-shaped figure, with about 7.5 cm (3 inches) more fabric allowance than slim cut for that line and little tapering at the waist. Shirts will hang straight from armpit to hip and are cut with the assumption that all parts of the arm and torso are proportionate, and the end of the shoulder seam should sit on the shoulder. Because of rising obesity levels in the world, shirts may be sold with additional clearance around the stomach area to prevent gaping or belling out around the stomach.
Choosing a fit
Slim or muscular men are most flattered by slim-fit T-shirts, while men of other builds are better suited to a normal cut. Men with broad shoulders are especially flattered by slim-fit shirts because the extra looseness at the waist in a normal fit will make the man appear shapeless and soft in the stomach. If the shirt is to be worn in hot areas or during heavy activity, a normal-fit T-shirt provides better ventilation and range of movement.