Two things you may not know much about—book arts and sister cities. I had little idea about these activities until friends introduced me, proving true the words, “I get by with a little help from my friends.”

These somewhat obscure subjects are coming together, however, on Friday, October 7, at the French Library. Entitled “The Ex-Libris Exchange,” this exhibit features books designed by 25 artists, thirteen from Boston and twelve from one of Boston’s sister cities, Strasbourg, France. It is sponsored by the Boston/Strasbourg Sister City Association or the BSSCA.

Let’s take book arts first. Artist’s books are growing in popularity with collectors. The Smithsonian and Harvard’s Houghton Library already have interesting collections. But don’t think Crime and Punishment when you think of book arts. Instead imagine beautiful paper, quirky shapes and sizes, inventive bindings, new ways of telling stories and many surprises when you open the book.

A friend of mine in Maine introduced me to these objects because she became a book artist. Her creations tell stories through phrases, lines, fabrics, collages, maps and other media and techniques. When you open one of her books, it might fold out into big shapes. Turn over the book, and it folds out in a different way. The books beg to be handled and manipulated, but that sometimes can’t happen because they are too fragile. Some of the artist’s books in the French Library’s exhibit can be handled, however, adding to your pleasure.

Watertown artist Ann Forbush got the idea for this show when she was in Strasbourg at an earlier artist’s exchange, sponsored by the BSSCA, called Par Avion, in which one artist would create an image, mail it to his or her colleague in the other city who would add to the image, and then they would mail it back and forth until the piece was complete.

While in Strasbourg, Ann and her fellow artists were treated to several behind-the-scenes tours. One visit was to a library with an impressive collection of rare manuscripts.

There Ann saw a journal of the Revolutionary War period in America created by Georg Daniel Flohr who fought with French soldiers in that war and returned home to the area around Strasbourg, which at that time was part of Germany. Rather than a description of military life, his journal presented the daily life of America. Handwritten and lavishly illustrated, it was unique and gorgeous. Ann believed it would inspire present-day Bostonians and Strasbourgians to create their own books. So she and a colleague in Strasbourg got the effort going. Check out http://exlibrisproject.com for a flavor of how varied the responses to one historic artifact can be.

The exhibit includes a facsimile of Flohr’s journal. When the exhibit moves to Strasbourg next spring, the real journal will be on display.

What about sister cities? You may not have realized Boston has ten of them plus three cities with which it has a “partnership relationship.” The BSSCA is the second oldest such alliance in Boston, established in 1960 at the urging of Charles Munch, a Strasbourg native who was then conductor of the Boston Symphony, according to Mary Louise Burke, president of the BSSCA.

Burke said the concept of sister cities was initiated by General Eisenhower at the end of World War II to foster understanding with foreign lands.

Different sister city relationships have different levels of commitment and activity. The Boston/Strasbourg connection is one of the most active, said Burke. Run by volunteers with no office or staff, the BSSCA has sponsored not only artist exchanges, but also exchanges of civic and cultural leaders, musicians, teachers, school kids, fire fighters, chefs and even a curator of wallpaper in partnership with Historic New England. Strasbourg’s cuurent mayor has been to Boston four times, Burke said, and several Boston mayors have visited Strasbourg. “We promote the culture of Alsace [the region of Strasbourg] to enrich Boston residents,” she said.

The organization raises money through dues and a few fund-raising events. One recent party was a “diner en blanc,” in which gourmands dressed in white as the French do to dine at Les Zygomates in the Leather District.

The late deputy mayor under Kevin White, Katharine Kane, was a strong supporter of sister cities, especially the alliance with Strasbourg, and her sister-in-law, Ann Collier, a Back Bay resident fluent in French, was president of BSSCA for 11 years and is still involved as treasurer.

The friendships formed are real and lasting, said Burke. The most moving moment for her was after the Boston Marathon bombings, when Strasbourg sent condolences and followed up with an invitation for a Boston runner to come to Strasbourg to run in its marathon. It also raised more than $15,000 from Strasbourg residents for Boston’s One Fund. Two Strasbourg runners who were unable to finish in 2013 because they were not allowed to proceed past Kenmore Square returned to Boston at the Strasbourg sister city organizations expense to run and finally cross the finish line in the 2016 Boston Marathon.

The exhibit is free and runs through October. The French Library is at 53 Marlborough Street.