Half a dozen fans clutch large paint rollers as they stand in the center of a dimly lit, cavernous warehouse in Northwest Portland.

Almost in unison, they carefully dip their rollers into pans of white paint before running them over a large canvas that they've laid out on top of the cement floor. A dozen more fans kneel over another massive piece of fabric on the other side of the large room, meticulously filling in the blank canvas with red, green and blue paint.

It's a tedious task. The painting alone will take a full three days and the combined efforts of more than 50 fans.

But the Rose City Riveters take immense pride in producing their tifos.

"We do it to encourage the team," Portland Thorns fan Chrissie McConnell said. "The players put all their heart and soul and passion into their game and this is something we can do to pay them back."

On Saturday, the Rose City Riveters, the Portland Thorns supporters group, unveiled their first tifo of the season, welcoming the players back to Portland with a three-part panel display. The tifo covered the stands in the north end of Providence Park for less than a minute immediately before the Thorns took on the Boston Breakers in their 2015 NWSL home opener.

Portland has long been known for its creative and quirky tifo displays thanks to the Timbers Army, who have become renowned around Major League Soccer for their intricate and expansive tifos, coordinated topical displays that the fans unveil in the stands before kickoff.

Since the Thorns' inaugural 2013 season, the Rose City Riveters have attempted to bring the same level of intricacy and attention to detail to their own tifo displays.

"We definitely take pride in it," Thorns fan Cory Coleman said. "We take pride in continuing the tradition that the Timbers Army really started...I'm really happy that we can continue this tradition with women's soccer and have it be on par with any sport."

The planning for Saturday's tifo began in March when members of the Rose City Riveters met at the 107ist Fanladen to throw out ideas. Different fans pitched bits and pieces, and slowly, through the brainstorming session and over Facebook, the design began to take shape.

The group decided that the tifo should focus on welcoming the distinctly international Thorns players back to Portland. They designed a map of the world, using red lines to track the path between each international player's home country and Portland. They crafted a fanciful Instagram photo, depicting shoes with the flags of different countries standing on the famous carpet at Portland International Airport. They decided the tifo should read, "Welcome to PDX: Where every game means the world."

"This is home," said Holly Duthie, who coordinated the project. "The concept is all about coming back to Portland from far away... It's about welcoming the team back."

After the group settled on the concept, Duthie, who works as a desktop publisher, brought the design to life on her computer. When it was all finalized, the group secured supplies - which included gallons upon gallons of paint - and finally managed to find a location where they could lay out the different panels and begin the work-intensive job of painting.

On the weekend before the April 11 home opener, the group spent three consecutive days at the warehouse in Northwest Portland painting each of the three panels that would ultimately make up the tifo.

"It's a great activity," Thorns fan Ben Platt said. "It's a really big scale, creative thing that you don't get to do too often."

On their first night at the warehouse, a group of fans began the slow process of using paint to white out a recycled banner from an old Timbers Army tifo. Another group employed a second-floor projector to project Duthie's design onto the other large pieces of white fabric. They carefully used chalk to trace the outlines of the design onto the banner. They returned the next day to slowly mix paint and begin to fill in the outlined design with the appropriate colors.

For hours, it looked as if they were hardly making any headway, but, like a puzzle, the design slowly began to take its final shape. By the end of the second day, their Instagram panel was already complete.

"I really enjoy the chaos and the camaraderie," McConnell said. "It just seems like an impossible thing that's never going to get finished and then it does. It's like magic."

In the weeks leading up to a game, the Rose City Riveters are always diligent about keeping any discussion of the tifo as a well-guarded secret. When it goes up at the stadium, it is intended to be a delightful surprise to the organization, the players and the rest of the fans in the stands.

On Saturday, the display captured the attention of the stadium for only a fleeting moment, before it quickly came down and the focus returned to the field and the match between the Thorns and the Breakers.

But the display had done its job and burned its way into the collective memory of the stadium crowd and the fans following along on social media. And, maybe in a small way, it also sparked the Thorns players on the field to their 4-1 victory.

"I'd like to think when the players see it, it motivates them a little bit," Duthie said. "Maybe it gives them that little edge."

-- Jamie Goldberg | jgoldberg@oregonian.com

503-853-3761 | @jamiebgoldberg