Several years ago, Ron Kaplan noticed how often the homeless people he saw walking around Chicago carried their belongings around in plastic bags. Kaplan, co-owner of a music booking agency called Monterey International, wondered if there might be a better solution. Although he was already volunteering with area homeless organizations, he says, "I wanted to do something more."

What started as a passing thought turned into reality after he met with Vernon Hills, Illinois-based High Sierra Sport Company, now owned by Samsonite. The backpack company started working on a design for what became the Citypak, a durable, specialized backpack for the homeless. Kaplan thought they'd make and distribute maybe 200 bags. Now in its fourth year, the Citypak Project has distributed 23,500 packs in U.S. and Canadian cities including Chicago, San Francisco, Los Angeles and Toronto.

Citypak, a program of Illinois 501(c)(3) non-profit the Selma Breskin Kaplan Foundation, has taken a unique approach to making bags that marries the needs of the homeless to market solutions. From design to distribution, execution of the project has been based on the kind of careful research and quick decision making critical to launching a profitable business -- only in this case, the point isn't to make money but to help a vulnerable population.

The project started with Kaplan and High Sierra hosting about 20 homeless people found through the Chicago Homeless Coalition for a focus group to critique preliminary backpack designs. Participants were provided with lunch in exchange for their time. The idea was to give people a tool to organize their things, something versatile enough to bring to a meeting with a coworker, job interview or school, or to have on hand during a night on the streets.

"The response was 'Oh my goodness,'" Kaplan said of the reaction to the waterproof bag. "And we realized that nothing has ever been addressed, nothing has been made for them."

Members of the focus group suggested adding a special pocket for the paperwork transient city residents often carry. People spoke about safety concerns such as having their bags stolen, especially while sleeping in shelters. To prevent theft, loops were added for users to to attach the bag to their limbs without having to wear it on their backs when sitting or lying down. A poncho component was added to make the bag easier to use in the rain.

High Sierra designer Mike Angelini,  who donated his time to crafting the Citypak, describes the bag as "completely different than any product I've ever worked on" in terms of design constraints.

"There wasn't like, 'Okay, we have to hit the price point," he says, though he still had to be cost conscious.

The bags fit the brand and mission of High Sierra to create thoughtful bags that suit the individual needs of the owners, says High Sierra product manager Monica Diaz, who also donated time to working on the Citypak. "We're able to give them the bag that was made for them in their situation."

If it were sold retail, the Citypak could go for $100 to $150, says Kaplan. Instead, it's strictly given away as a donation to people who really need it, with High Sierra fronting a portion of the cost and the remainder coming from donations.

But that hasn't quashed interest in buying the bags. Attendees of trade shows often try to buy the bag from High Sierra's booths, says Diaz. "I've been begged for one of the bags and I don't want to take it away from someone who needs it to give it to someone who wants it," she says.

To satisfy consumers, High Sierra came up with the Publicpak, a bag based loosely on Citypak designs, with a portion of revenue going towards the cost of manufacturing the charity bags. A one-to-one sales to distribution ratio would be difficult given that the Citypak is considerably more expensive to produce than the Publicpak, notes Diaz. Manufacturing and distribution costs for bags are otherwise covered by a mix of private donations and contributions from High Sierra, Citypak and non-profit distributors.

You can think of the Citypak as a sort of lubricant for social services, both in its physical utility and in how it's marketed. Distributions often coincide with the offering of other public services; in Boston, for example, bags were given out at an event registering homeless city residents for health services.

While non-profit distributors are carefully selected, Kaplan says he doesn't belabor determinations of where to distribute. If it seems like a city has a need, Citypak finds a way to go.

"You don't analyze it, you just say 'Okay, we need 200 backpacks, let's do it,'" he says.

Bags are as much about communicating the needs of the people living transiently to others as they are about satisfying at least some of those needs, says Kaplan. "This wasn't just about giving a backpack but talking about issues of homelessness."

Looking forward, Citypak is working on making it easier for individuals to donate bags to homeless loved ones and acquaintances. The program hopes to bring the total of bags distributed to 50,000 by 2017. Also, in response to clamor for a bag even more similar to Citypak than the Publicpak, Angelini is working on a new design for a bag to sell to consumers.

"It just takes time. We're in our fourth year, we're just learning a lot of stuff. We all have other things that we're doing," says Kaplan. After all, he and people at Sierra are donating time to Citypak on top of their full-time jobs. "We feel good about what we've accomplished so far."