The banner will be hard to miss, since it's 100 feet high by 40 feet long, says PEMCO spokesman Jon Osterberg.
"If it were hung over the edge of the building it would extend all the way down to the sidewalk and across the street adjacent so this thing is really large."
The company is hoping to get at least 12,000 fans to sign it over the next week before it's sent to New Jersey. They'll be taking it around town to various events where fellow 12s can offer their support to the Seahawks.
"Our thinking is it's a way to unite our Seahawks community and it's going to rally our team even from 3,000 miles away," Osterberg says.
Click here for a list of where you can go to sign the banner.