When word leaked out a few years ago about a new Star Wars movie code-named “Red Cup,” it wasn’t hard to guess which character would be its hero. Red Cup? Well, the most famous red cups known to mankind are probably those ubiquitous plastic receptacles manufactured by Solo Cup Company. Solo? Get it? Of course, the movie would be about Han Solo, the wisecracking rogue who pilots that rickety but surprisingly durable spacecraft, the Millennium Falcon.

Solo Cup has hopped onboard—Solo plates and cups are for sale in packages emblazoned with pictures of the young Han Solo and his hirsute helmsman, Chewbacca. And a big model of the Millennium Falcon fashioned out of the company’s red cups was on display May 10 at Hollywood’s red-carpet premiere of the movie.

While Star Wars fans are eager to learn more about Han Solo’s origin story, Solo Cup’s Chicago origins have long been a subject of fascination for design nerds. What are the secrets behind the success of this company’s seemingly simple but omnipresent products?

Before Leo Hulseman started the company on Chicago’s South Side during the Great Depression, the South Dakota native was a salesman for Vortex Manufacturing Company in Chicago, which used a machine patented in 1920 by local inventor David F. Curtin to make cone-shaped paper cups. Paper cups were in demand because of concerns about hygiene. Before the early 1900s, it had been common for people to drink water out of shared cups, but the twentieth century brought a growing awareness that this was a great way to ingest germs. In 1911, the Chicago City Council outlawed the use of “common drinking cups”—or the “Cup of Death,” as a Tribune headline put it—in “any building or place open to the public, or in any lodginghouse or boardinghouse, factory, office, store, or private school.” (The ordinance is still on the books.)

In 1936, Hulseman founded his own business—originally called Paper Container Manufacturing—selling a similar paper cone. “He built a machine in his garage,” recalls grandson Paul Hulseman. “He would make the cups at night and sell them during the day.” The business soon took over an old ice plant at 75th Street and East End Avenue in the South Shore neighborhood.

The company’s 4.25-ounce cones were easy to pull from dispensers next to water coolers in offices and places like golf courses. “It’s the ultimate disposable, because it couldn’t be put down,” Paul says. Leo Hulseman later credited his company’s growth to an automatic paper-cup-making machine, which could churn out 250 cups a minute from a roll of paper. He bought that machine in 1940 from its inventor, George Method Merta, a Chicagoan who’d immigrated from the tiny mountain town of Metylovice in Czechoslovakia.

Hulseman’s company soon started using the Solo name. Paul Hulseman says he heard a family story explaining what it meant: “My uncle John, my dad, and my grandfather were sitting around the kitchen table one day. ‘Solo’ came up—as in ‘So high in quality, so low in price.’” But according to a 1965 court decision in a patent lawsuit brought by Solo against a competitor, Merta was already using the Solo name when Leo Hulseman bought Merta’s cup-making machine. Merta “made a design for the paper, selected the name Solo for the cups, after a suggestion from his wife that it would be a good name for a one-use disposable container, and had the design printed on the roll of paper by a printer in Chicago,” the judge noted. Although she isn’t mentioned by name in the ruling, the woman who came up with the Solo moniker was Czech immigrant Bozena Merta. And it was Bozena herself who’d patented a conical drinking cup in 1936—a design she stumbled upon while working with a paper heart on a Valentine box. (The Mertas moved to Los Angeles, where George died in 1975 and Bozena in 1989.)

Over the decades, Solo operated various plants around the Chicago area; eventually, the company moved its headquarters to Highland Park and Lake Forest. In the 1960s, Solo introduced the Cozy Cup—disposable, single-use inserts placed inside a reusable coffee cup holder. Meanwhile, shoppers began finding 45 rpm records by Dora Hall inside Solo’s packages. Who was this mysterious senior citizen singing songs like “Hoochi-Koochi” and “Satisfaction”? It was none other than Leo Hulseman’s wife, Dorothy, who’d performed on the vaudeville circuit in her youth. She took up singing again at her husband’s insistence, after she was diagnosed with breast cancer in 1959. “He was very focused on giving her something to do,” Paul Hulseman explains.

In comments that appeared in the St. Louis Post-Dispatch in 1974, Hall said she sang “practically every kind” of music. “I sang jazz, Western, folk, children’s songs, ballads,” she said. “You see, Leo… and I bought this big tape-recording machine and we started fooling around with it, with me singing. We decided to try to sell the records and they were big hits.” They weren’t really hits—not according to Billboard, anyway. But these records did find their way into countless homes, smuggled in via cup packages.

In 1966, nine of her grandchildren appeared on the television show I’ve Got a Secret, hosted by Steve Allen. “Our secret was our grandmother just released her first rock ’n’ roll record,” Paul recalls. “When they figured it out, my grandmother came out and sang a song.”

Solo Cup produced syndicated television specials in 1971 and 1974, starring Dora Hall alongside Frank Sinatra Jr., Rich Little, and Scatman Crothers. “I do these shows to keep from being a meddling old grandmother,” Hall remarked. TV critics weren’t kind. “Dora Hall has set a precedent—television’s first vanity hour,” Indianapolis News critic Richard K. Shull wrote in 1974. One confused viewer wrote to a syndicated TV column, remarking: “I recently saw the oddest show, ‘Dora’s World.’ Who in the world is Dora Hall? It seemed she was an amateur being catered to by professionals.”

“Some people get kind of mean about it,” Paul Hulseman says, adding that he enjoys the records of his grandmother—who died in 1988, three decades after her bout with cancer. “I love them, because they’re my grandmother. I think ‘camp’ would be a nice way to put it.” Dora Hall now has something of a cult following; one blog calls her “The Queen of the Vanity Records.”

Paul Hulseman says his grandparents’ records and TV shows were more than a vanity project. “It was all about selling cups,” he says. “To get a product on the shelf is difficult and expensive. Grandpa would go to the grocery stores and… he bartered TV ads for shelf space.” In addition to his work in music and television, Leo Hulseman (who died in 1989) also was also active in the sport of polo, playing as the Solo Cup team’s captain at the Oak Brook Polo Club.

Around the same time “plastics” was a punch line in 1967’s The Graduate, Solo Cup was seeking a better way to make cups out of the stuff. Paul’s father, Robert, found machines in Germany that extruded plastic in multiple layers. This made it possible to make cups with one color on the exterior and another color on the interior. “A white interior made it much more appealing,” Paul says.

One day, Robert showed up at the family’s house in Winnetka with a bunch of plastic cups—some eighteen different color combinations. “He said, ‘What do you kids like?’” recalls Paul, who was around ten years old at the time. “We were his marketing.” The kids helped choose the original colors for Solo’s new cup, which made its debut in the 1970s: red, blue, yellow and peach. “We didn’t do very well on the peach,” Paul remarks. “Yellow was huge in Texas.” And red was popular everywhere.

In an article for Slate, Seth Stevenson argues that the cup’s sturdy design is responsible for its success, calling it “the Sherman tank of disposable mealware.” Country star Toby Keith sang its praises in his 2011 goofball hit, “Red Solo Cup”:

Now, red Solo cup is the best receptacle
For barbecues, tailgates, fairs, and festivals
And you, sir, do not have a pair of testicles
If you prefer drinking from glass
Hey, red Solo cup is cheap and disposable
And in 14 years, they are decomposable
And unlike my home, they are not foreclosable
Freddy Mac can kiss my ass

Two pairs of brothers, Brett and Brad Warren and Brett and Jim Beavers, wrote that ditty without intending to pitch it, but Keith happened to hear it. “It is the stupidest song I ever heard in my life, but it’s so stupid it’s good,” he told The Boot website. “‘Red Solo Cup’ is like a squirrel loose in a church house. We can play it in an office and then play five other songs, give it an hour, walk out, and you’d hear the receptionist singing it. It’s like nursery rhyme stupid.” (Contrary to the lyrics, these polystyrene cups “are not, in fact, decomposable,” an article on the Recycle Nation website notes.)

Former Solo CEO Robert Hulseman, who died in 2016, “never envisioned the red Solo cup being so tied in with keggers and parties and things like that,” his son Paul says. But Brea Keating, Solo’s brand social media manager, says the company embraces the cup’s place in popular culture. “We do think of the cup as a character,” she says.

“It’s just this emotional connection people have to this brand,” says Kim Healy, Solo’s vice president for consumer products marketing and innovation, who has worked for the company since 1998. Solo has tweaked the design of its iconic party cup, adding indented grooves in 2003 so that the cup would be easier to grip. In 2009, the cup’s base was squared and the ergonomic grips were refined. “Consumers loved it,” Healy says. (But in his Slate article, Stevenson makes the case for the purity of the cup’s original circular design.)

Another hallmark Solo product solved a hot problem, as a New York Times Magazine article explained: “In the late 1970s, when you ordered coffee to go, you usually had to tear a hole in the plastic lid if you wanted to drink through it. This maneuver was so awkward that you risked burning your hand.” And so, in 1986, Solo patented the Traveler Lid for coffee cups. “My dad and a guy named Jack Clements designed this thing,” Paul Hulseman recalls. “They designed it after a baby sipper cup. Rather than pour the liquid into your mouth, you have to kind of suck it out of the cup.”

There’s a recessed area on the lid, next to the opening. That’s where your upper lip goes while you suck coffee out through that little hole. As the patent explains, this will “facilitate drinking while walking or traveling in a moving vehicle without spillage.” The lid spread far and wide when the burgeoning Starbucks chain placed it atop zillions of coffee cups. And New York’s Museum of Modern Art featured the widely praised lid in a 2004 exhibit of “Humble Masterpieces.”

Even as the Hulsemans’ creations continued to gain prominence, the family lost control of their company to a private equity firm in 2006. Solo was a $1.6 billion company when it was acquired in 2012 by Dart Container Corporation, based in Mason, Michigan. But Solo, which now has offices in Lincolnshire, remains a strong brand.

Some people have suggested that George Lucas was thinking about Solo cups in the 1970s when he named one of his Star Wars characters Han Solo. Maybe, maybe not. “Basically, I developed the names for the characters phonetically,” Lucas told The New York Times in 1997. Now, it turns out that Han Solo may not be the hero’s actual name at birth. Last year, Disney CEO Bob Iger said the new movie will explain how the character got his name.

The answer to that mystery is unlikely to involve any product placement. As Solo Cup Company noted in a statement: “Unfortunately Han Solo lives in a galaxy far, far away, so don’t expect to see the Solo cup integrated into the movie.”