Anyone can put a sandwich in a baggie. But try packing a full-course meal, and you'll be lugging around a drawer's worth of Tupperware. "The Japanese solved that problem with Bento boxes," says Dan Black, who co-owns the London-based design firm Black + Blum. Yet, as of mid-2009, there wasn't an equivalent solution in America. So Black and partner Martin Blum set out to create one.
Although the name of the final two-piece product, "Lunch Pot," had to be straightforward enough to appeal to an international market, the team got playful by inscribing the rim with food-loving quotes, such as George Bernard Shaw's, "There is no sincerer love than the love of food." Here, we track the creation of the product. ($22, black-blum.com)
 Black + Blum's first next-gen lunch tote, the Bento Box, sold 100,000 units within nine months of its May 2010 launch. However, its cubic dividers precluded a sizable market: people who snack on amorphous foods, such as yogurt, soup, and salad. "For them," says Black, "we needed something potlike."
 "It looked like a zeppelin," says Black of an initial product sketch, whose liquids-only top compartment was quickly dismissed as overkill. "We wanted to make a food carrier, not a water bottle."
 Early prototypes (see white, pictured) had bulky, thermal-insulation strips and lids that sealed via "friction fit." "The whole thing felt precarious to open near a keyboard," says Black, whose team fashioned new models with simple screw-off tops (see yellow, pictured), designed to mimic the aesthetic of old-school Mason jars, as in the final product (see green, pictured).
 During transit, a strap mechanism holds both containers in place as the weight of their contents keeps everything taut. Once empty, the smaller pot stacks into the larger one to save space.
 To engineer the perfect spork, all 12 Black + Blum employees spent four months using different models to lunch on soup and noodles. "I liked the white prototype," says Black of the rejected jumbo-size design, "but my staff said it was just because I have a big mouth."
A version of this article appeared in the June 2011 issue of Fast Company magazine.