Sling bag

A messenger bag (also called a courier bag) is a type of sack, usually made out of some kind of cloth (natural or synthetic), that is worn over one shoulder with a strap that goes across the chest resting the bag on the lower back. While messenger bags are sometimes used by couriers, they are now also an urban fashion icon. Some types of messenger bags are called carryalls. A smaller version is often called a sling bag.

This design of bag has been used in the transportation of mail and goods by numerous types of messengers, including Pony Express riders, postal workers, messengers on foot (especially in ancient times), and bicycle couriers. Some Royal Mail carriers in the United Kingdom currently use large messenger bags to deliver mail in lieu of a Postbag.

The design of the modern messenger bag traces its origin to the utility lineman's bag of the 1950s made by De Martini Globe Canvas Company, which was founded by Frank De Martini and run with his two daughters, Kathleen and Marge. The bags originally allowed linemen to carry necessary tools within easy reach while climbing utility poles.

De Martini messenger bags were made of cotton canvas with a waterproof lining, a cotton webbed shoulder strap and two closure straps. Bags had one small internal pocket for invoice slips. De Martini Globe Canvas messenger bags originally bore no manufacturer's label, and were sold only to, and issued by, New York City messenger services, and not sold in stores. Globe Canvas supplied bags for most New York messenger firms through the 1970s and 1980s. The larger messenger firms issued riders bags in exchange for a deposit. Bags were color-coded by firm, with the two largest companies, Mobile Messenger and Can-Carriers, using red and blue bags, respectively.

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