A T-shirt is a style of fabric shirt named after the T shape of its body and sleeves. Traditionally it has short sleeves and a round neckline, known as a crew neck, which lacks a collar. T-shirts are generally made of a stretchy, light and inexpensive fabric and are easy to clean.

Typically made of cotton textile in a stockinette or jersey knit, it has a distinctively pliable texture compared to shirts made of woven cloth. Some modern versions have a body made from a continuously knitted tube, produced on a circular knitting machine, such that the torso has no side seams. The manufacture of T-shirts has become highly automated and may include cutting fabric with a laser or a water jet.

The T-shirt evolved from undergarments used in the 19th century and, in the mid-20th century, transitioned from undergarment to general-use casual clothing.

A V-neck T-shirt has a V-shaped neckline, as opposed to the round neckline of the more common crew neck shirt (also called a U-neck). V-necks were introduced so that the neckline of the shirt does not show when worn beneath an outer shirt, as would that of a crew neck shirt.

Packs hang from the shoulders or are supported by a combination of straps around shoulders and waist or hips. Types range from the frameless rucksack, hung from two straps, and the frame rucksack, in which the pack is attached to a roughly rectangular frame hung on the shoulder straps, to the contour frame pack, with a frame of aluminum or magnesium tubing bent to follow the contour of the back. The Kelty-type pack, which is used with the contour frame, employs a waistband to transfer most of the weight of the pack to the hips.

Modern materials have revolutionized backpack construction, utility, and capacity.

The earliest packs were made from canvas, which, while strong and durable, added considerable weight for the backpacker to manage and lacked resistance to the elements. Today’s packs are constructed of nylon or similar lightweight materials and are usually at least partially waterproof.