The Aloha shirt is a style of dress shirt originating in Hawaii. It is currently the premier textile export of the Hawaii manufacturing industry. The shirts are printed, mostly short-sleeved, and collared. They usually have buttons, sometimes as a complete button-down shirt, and sometimes just down to the chest (pullover). Aloha shirts usually have a left chest pocket sewn in to make the printed pattern continuous. Aloha shirts may be worn by men or women; women's aloha shirts usually have a lower-cut, v-neck style. The lower hem is straight, as the shirts are not meant to be tucked in.
Aloha shirts exported to the mainland United States and elsewhere are called Hawaiian shirts and often brilliantly colored with floral patterns or generic Polynesian motifs and are worn as casual, informal wear.
By contrast, men's aloha shirts manufactured for local Hawaiian residents are usually adorned with traditional Hawaiian quilt designs, tapa designs, or simple floral patterns in more muted colors. Aloha shirts manufactured for local consumption are considered formal wear in business and government, and thus are regarded as equivalent to a shirt, coat, and tie (generally impractical in the warmer climate of Hawaii) in all but the most formal of settings. These shirts often are printed on the interior, resulting in the muted color on the exterior, and are called "reverse print"; this is often mistaken for the shirt being worn inside-out.
The related concept of "Aloha Attire" stems from the Aloha shirt. Semi-formal functions such as weddings, birthday parties, and dinners are often designated as "Aloha Attire", meaning that men wear Aloha shirts and women wear muumuu. Because Hawaii tends to be more casual, it is rarely appropriate to attend such functions in full evening wear like on the mainland; instead, Aloha Attire is seen as the happy medium between excessive formality and casual wear. "Aloha Friday," a now-common tradition of celebrating the end of the workweek by wearing more casual attire on Fridays, initially grew out of an effort to promote aloha shirts.
The modern Aloha shirt was devised in the early 1930s by Chinese merchant Ellery Chun of King-Smith Clothiers and Dry Goods, a store in Waikiki. Chun began sewing brightly colored shirts for tourists out of old kimono fabrics he had leftover in stock. The Honolulu Advertiser newspaper was quick to coin the term Aloha shirt to describe Chun's fashionable creation. Chun trademarked the name. The first advertisement in the Honolulu Advertiser for Chun's Aloha shirt was published on June 28, 1935. Local residents, especially surfers, and tourists descended on Chun's store and bought every shirt he had. Within years, major designer labels sprung up all over Hawaii and began manufacturing and selling Aloha shirts en masse. Retail chains in Hawaii, including mainland based ones, may mass produce a single aloha shirt design for employee uniforms.
Text adapted from Wikipedia.