For 20 years, Janet Kaiser wondered what happened to the Pittsburgh Friendship Quilt, a project of the Buhl Science Center in the late 1980s. And if another quilter, Elizabeth Jones, hadn't been laid up with a knee injury, it might never have been found in time for an exhibit last year.

The quilt, featured at the Heinz History Center's second annual Quilters Weekend tomorrow and Sunday, comprises more than 32,000 fabric squares, almost all carrying the name of a Pittsburgher.

It was a citywide project; the 2.25-inch squares were signed at the Buhl, in schools and at many other places around town. Presidents Nixon and Ford, Ronald and Nancy Reagan and Lady Bird Johnson also signed and returned squares, as did many of the city's professional athletes.

Under Mrs. Kaiser's leadership, volunteers sorted all of the squares by color and machine-pieced them into panels, creating a kaleidoscopic rainbow of fabric. The quilt's 21 panels, each 8 feet tall, together run to 80 feet. Displayed on Plexiglas panels at the Buhl for six months in 1988 and 1989, the quilt later was put into storage. But where?

Mrs. Kaiser wrote letters in 2007 in an effort to track it down for the Pittsburgh 250 celebration, but to no avail. In early 2008, as Ms. Jones was recuperating, she happened on Mrs. Kaiser's 1990 story about the project in Quilters Newsletter magazine and determined to find the quilt so that it could be exhibited in the Quilt Company East's summer show in Monroeville. With persistence, the quilt was discovered, slightly damaged but mostly intact, in the basement of Carnegie Science Center's SportsWorks building, then still open but slated for demolition.

After Quilt Company East members repaired the quilt, it appeared in the guild's Monroeville show last summer and this weekend will be featured in a fifth-floor gallery at the Heinz History Center.

"The squares are fun to read," said Mrs. Kaiser, who thought the quilt was lost forever. "GO PENS! Yea Steelers! Joey (heart) Maria ... and many others." Last summer, people came to find their squares.

The Quilters Weekend, 11 a.m. to 3 p.m. today and tomorrow, also includes displays and hands-on activities for all ages, vendor and quilt guild tables and a swap shop, where unfinished projects and quilt books can be donated or purchased for a small donation. Quilters Weekend events are included with museum admission ($9 adults, $5 children ages 6-18, free for children under $5); the center is at 1212 Smallman St., Strip District. Information: heinzhistorycenter.org.

For more information about the Pittsburgh Friendship Quilt, visit quiltpittsburgh.org.