The red Solo Cup is an elegant piece of technology.

It's easy to forget when you find them strewn across the room, half-filled with leftover beer or crushed underfoot from parties the night before. But what many take for granted as simply a cheap, disposable beverage holder is the result of careful, beautiful engineering by people such as Robert Hulseman.

Many are now pouring one out for Hulseman, whose family on Thursday broke the news of his passing on Dec. 21. He was 84.

Early in his career, Hulseman helped his father run the Solo Cup Co., which like many of its competitors spent decades making disposable cups out of paper. In fact, the very first Solo Cup was a paper cone that debuted in the 1940s, according to a company historical fact sheet. Although Hulseman would later become chief executive in the 1980s, he played a central role in the 1970s developing the plastic cups that many of us love today. That wasn't Hulseman's only innovation, either: He was also one of the people behind the original Solo traveler lid, the plastic covers you can find on to-go cups around the world.

While regular users may admire the Solo Cup's lightness and balance, particularly when filled to the brim with libation, some of the most underappreciated aspects of the cup can be traced to a simple design aimed at solving a rather sticky problem.

Before the invention of the Solo Cup as we know it, it was often difficult to remove one disposable cup from a whole stack because of the way they sometimes clung together, and designs aimed at eliminating the issue resulted in production irregularities that drove up costs and increased the likelihood of cup breakage. For a thing whose whole job is to hold other things, this outcome simply would not do.

Enter the plastic Solo Cup, which won a patent in 1976. Described as "an expendable thin walled cup for liquids and the like," the Solo Cup offered two key innovations that, according to the company, helped solve the sticking associated with large stacks of cups as well as the hard problem of cleanly removing the plastic cups from the production molds.


(Solo Cup Co. / USPTO)

One of the Solo Cup's distinguishing features, according to the patent, was the curved lip of each cup (see 10a in Fig.3). When several cups were stacked together, the lips would "engage" — to use the company's language — and rest upon each other, keeping one cup from sinking too tightly into the next.

But, Solo Cup Co. observed, this helped create another problem. When cups like these were subjected to crushing forces from various angles, the bottoms could warp in ways that actually made it harder to separate the cups. So the bottoms had to be reinforced (see Fig. 4, Fig. 6 and 26-28 in Fig. 3). This is how the plastic Solo Cup gained indentations or divots in the base that made the bottoms more rigid and allowed for more air flow between each stacked cup, which allegedly had the side benefit of helping the cups come apart.

It's often said, incorrectly, that the lines found on some Solo Cups were intentionally designed to mark appropriate serving sizes for different types of drinks, such as beer, wine and liquor. But this has been debunked by the Solo Cup Co.'s parent company, Dart Container Corp. The lines are meant to enhance "functional performance" and help keep your fingers from slipping.

(While we're at it, red Solo Cups did not come before blue; they were launched at the same time along with yellow and peach-colored variants, according to the Hulseman family.)

In the years leading up to Dart's acquisition of Solo, the cupmaker revised its iconic design several times. Solo filed a separate patent application in 2005 describing a plastic cup boasting "improved structural integrity."

"One disadvantage to many existing cup and container designs is that the round design is not conducive to gripping, a problem encountered with all cup designs, but especially in larger-volume cups," the filing reads. "The user must often exert more than a desirable amount of gripping pressure, in order to stabilize a cup that is too large to wrap fingers around."

The consequences of too much grippage could be dire, Solo went on to say, because it could cause the cup's walls to bend.

"A deflection of this sort may constrict the volume of the container causing unpleasant fluid overflows," the application read.

The company's solution was to add two vertical indents running down the side of the cup, and a further revision in 2009 sought to make the base more stable by adopting a square shape. But even these changes were carefully planned so as not to disturb the two fundamental principles at the heart of Hulseman's original vision: the Solo Cup's seamless nesting properties, and its ease of manufacturing.

That some of these engineering decisions might be overshadowed by the Solo Cup's cultural cachet is natural. But the company's devotion to practicality is only part of the allure, said Steven Heller, co-chair of the MFA Design Department at the School of Visual Arts in New York. The rest is fashion and marketing.

"I love the name Solo," said Heller. " 'The Solo Cup' suggests this is the one cup that you should use."