After 100 years, no one knows how Chevy came up with the bowtie logo.

Every logo in the auto industry has some kind of touchstone history. The Ford script was designed by one of Henry Ford's draftsmen; the Mercedes three-point star by Gottlieb Daimler in a drawing, and Kia's oval logo was meant to fit the same space as Ford's oval so that it could build cars for itself on the Korean assembly line it rented to Ford with not much trouble. But on the 100th anniversary of Chevy first using a bow-tie shape as its logo, its true origins remain hazy. Here's the leading theories on how that gold cross came to be.

The Wallpaper theory

William C. Durant, the auto empire builder who founded General Motors, long claimed that he had first seen the bowtie emblem in the wallpaper of a Paris hotel room in 1908. Durant said over the years that he was so struck by the design he ripped a piece of the paper off the walls for safekeeping in his wallet, and finally put the shape into use in 1913 for the newly-formed Chevrolet company. As this was the original origin story, every one that's followed has cast doubt on its authenticity.

The Napkin theory

In 1923, Durant's daughter, Margery, in her book "My Father," recounted how Durant liked to doodle on napkins during dinner, the pre-transistor age compliment to impolitely checking one's iPhone at the table. “I think it was between the soup and the fried chicken one night that he sketched out the design that is used on the Chevrolet car to this day,” she wrote. In that there's no other evidence for this theory, and it came many years after the Bowtie's creation and use, no one seems to believe it.

The Coalette theory

The strongest case comes from another of Durant's survivors, this time his widow, Catherine, in an interview given in 1976 but not published until 1989. She recounted being on vacation with Durant in Hot Springs, Va., in 1912, and that while reading a newspaper in their hotel, Durant showed her a design and said “I think this would be a very good emblem for the Chevrolet.”

Further research revealed that newspapers in the South of that era often ran ads from theSouthern Compressed Coal Company for "Coalettes," which were used in stoves in place of wood. The Coalette badge has the same slanted bow-tie outline that would make its first appearance for Chevrolet in October 1913, in an ad in the Washington Post; for decades after, Chevrolet ran its name inside the shape, just as the original Coalette brand did, and has alternated colors from the original black to blue to red and the gold that has been the core for more than a decade. But the basic shape has remained the same — an example of an enduring idea for a logo, whomever came up with it first.