BANGOR, Maine — When students and parents attend the open house nights at Bangor’s Downeast School on Aug. 21 and 30, they’ll come home with more than class schedules and paperwork.

Thanks to the donation of 512 backpacks loaded with pens, pencils, glue sticks, rulers, notebooks, scissors, binders, sharpeners, crayons and construction paper, the families of students in grades pre-kindergarten through eight at Downeast School and Indian Township School will have a little extra money for clothing or other needed items.

“It’s incredible. It’s a company that provides opportunities for schools to get furniture and supplies at a reasonable cost,” said Betsy Webb, Bangor schools superintendent. “We’re estimating the value of the donation to be $12,000 to $13,000.”

The company responsible for these donations is Portland-based Ruth’s Reusable Resources, an 18-year-old nonprofit organization founded by CEO Ruth Libby to transfer surplus business supplies and merchandise from companies such as OfficeMax, Staples, Office Depot, Jo-Ann Fabric, Elmer’s Glue and Dixon Ticonderoga into the hands of schoolchildren and teachers.

“This is the ninth year of our backpack program,” said Libby, who was directing the placement of supplies at the noisy Portland warehouse during a telephone interview.

This year, Ruth’s is helping 14 schools statewide. Downeast will get 370 backpacks for its students and Indian Township will get 142.

Ruth’s Reusable Resources began literally as a basement operation at Libby’s house after she saw an article about a woman gathering excess materials and castoff supplies and donating them to local schools.

“I had three boys in school at Scarborough and a teacher asked for some supplies for art projects,” Libby said. “So I started saving things and passed on requests for other people to use, even empty disposable coffee creamer cups for glue containers.”

The operation grew and had to be moved to a large room rented from the Scarborough school department to its current headquarters, which was purchased from Fortune 500 company Unum for $635,000 in 2007.

Ruth’s is open year-round and provides supplies free to teachers from schools that pay an annual membership fee with the nonprofit.

“Supplies come from all over the country, literally,” said Libby. “There are 26 free stores nationally for schools and we are the biggest in terms of supplies donated.”

Ruth’s will be transporting Indian Township’s supplies via truck on Monday to Brewer High School, where it will meet another truck from the Indian Township school.

Richard Fournier, Downeast School principal, will drive a truck down to Ruth’s Reusable Resources 28,000-square-foot warehouse and 9,000-square foot store in Portland on Tuesday to get the backpacks.

“I’m excited to go down to meet her and take a tour,” said Fournier. “It means the world to have someone be willing to step up and make a sizable donation like this in the Downeast School community.

“Words can’t express my thanks to Ruth and her organization. It’s remarkable.”

Libby said she uses information provided by the Maine Department of Education’s database and a rough formula to evaluate and identify schools in need. Schools with a total number of students on free or reduced-lunch plans constituting at least 75 percent of the total enrollment are eligible.

“We also try not to duplicate schools,” Libby said.

The schools on this year’s backpack list are Governor James Longley and Montello schools in Lewiston, Portland’s Riverton School, Downeast, Indian Township, Troy Central, Guy E. Rowe of Norway, Agnes Gray of West Paris, Oxford Elementary, and five other schools — in Arundel, Biddeford, Dayton, Old Orchard Beach and Saco — through an arrangement with the United Way.

With 92 percent of its student enrollment receiving free or reduced lunch rates, Downeast was an easy choice for Libby’s organization. Indian Township’s percentage of free- and reduced-lunch students is 84.6.

“These backpacks are roughly $30 apiece, not to mention all the supplies, so that’s probably $40 to $50 a family can save,” said Fournier. “The reaction has been extreme gratitude and thanks from parents. Being able to use that money in other ways is a big benefit, especially in these tough economic times.”