The 2015 shipping delays on the West Coast that caused several krewes to fear they would not receive their merchandise in time for their parades reminded us all how integral throws have become to Carnival in New Orleans.

Turning traditional spectator parades into crowd-participation events, throws are one of the elements that distinguish Mardi Gras parades in this city from those staged elsewhere.

No one is sure exactly when the tradition started. Carnival historian Henri Schindler credits Creole maskers in carriages tossing bonbons and flowers to women and children on balconies and banquettes.

Throughout the celebration’s early years, individual float riders occasionally tossed favors, but Rex formalized the practice, with all members participating in 1922. According to Schindler, photographs of the 1922 parade show everyone in the crowd with their arms outstretched, trying to catch the strands of glass beads and bracelets.

With its 1960 introduction of the first doubloon, Rex gave birth to the krewe-signature throw industry, which featured only doubloons for several years. In the late 1960s, glass beads from Czechoslovakia were phased out and replaced by plastic necklaces from Hong Kong. “Bogus bucks” were issued by a half-dozen clubs, starting in 1973. Rex tossed the first emblem necklace in 1974.

J. Clark Promotions made the popular “Carnival Coasters” starting in 1978 and produced krewe-logo flying discs the next year. Metairie’s Krewe of Mardi Gras threw the first logo cup — a soft Dixie Cup — in 1979. Giacona Container Co. produced hard plastic cups for the Krewe of Alla the next year, starting a whole new genre of collectibles. Mardi Gras collector cards ran from 1992 to 2001. Krewe d’Etat threw the first blinking beads in 1999.

There are three basic varieties of throws: generic (available to all krewes), logo (with the krewe’s crest emblazoned on the items) and signature (created for only one krewe, like Zulu coconuts, Muses shoes and Nyx purses).

Illuminated items are the most popular. Wearable items also are in demand, including hats, visors and sunglasses. Some krewes — such as Chaos, d’Etat and Muses — memorialize their parades by handing out printed depictions of their floats.

Competition among clubs to produce unique throws is fierce, with clubs such as Tucks, Nyx, Thoth and Muses importing more than 40 logo items each year.

Thoth minted 30 different doubloons this year.

Mardi Gras throws have become a multimillion-dollar industry. In addition to delighting the parade crowds, throws provide a revenue source for the clubs, because the items are sold to members at a profit. In some krewes, a rider must purchase a minimum “throw package” from the club. In most krewes, the amount spent on throws is up to the individual rider.

A movement promoting local and “green” throws has failed to gain much momentum, due in large part to the cost.

In 2015, Rex introduced float-specific plush pillows, medallion beads and cups — a new tradition for Carnival’s oldest parade.