Not long after I started toting library books to my grandchildren’s houses, one of my daughters gave me a gift: a sturdy canvas bag with wide handles and, on the side, a photograph of my three grandchildren and me reading.

I treasure the bag, not just because of the photo, not just because of the words above the photo — “Fresh Books” — but because it means my daughters and sons-in-law are okay with my BYOB habit. It’s not as if their houses aren’t already strewn with books. It’s not as if I’m trying against all odds to talk these grandchildren into reading. It is a lot like I’m showing up at the beach with a sandbox.

But it’s different sand. It’s sand they haven’t seen before, usually. Sometimes, they have seen it before. “We already read that,” they’ll say. But — and this is one reason I love them — they usually add, “Read it again anyway.”

I brought my first bag of “Fresh Books” to my granddaughter’s house. My husband and I were babysitting, and I thought the books would be something up my sleeve should we run out of diversions. But the books were never last-resort entertainment. They’ve always been the first resort.

“What’s in the bag?” my granddaughter asked when I walked in. Thirty seconds later, we were reading the bag’s contents. And ever since, “Do you have your bag of books?” she and her older cousin ask every time I show up. Somehow, the bag is like Mary Poppins’ carpet bag, like Santa’s sack, like a magician’s hat. Anything might be in there.

As children, my sister and I described the spoils of successful library visits, when we found both never-before-read titles and old favorites we couldn’t wait to read again, as “fresh, juicy books.”

“I love curling up with fresh, juicy books,” we’d say. When I introduced the phrase to my grandchildren, they picked it up as readily as they’d pick up a nickel on the sidewalk. “Do you have fresh, juicy books?” they ask when I lug in the overloaded bag. (I tend to get carried away. You’d think I was checking out books even as the library was burning down.)

I keep the bag in the car so it’s always wherever I am. This arrangement has had two distinct results: I’ve found myself reading in a variety of places, and the bag is filthy. Not long ago, we rented state park cabins for a family getaway. The cabins were lined up one-two-three along a park road, and for several days we led a symbiotic existence, breakfasting here, dining there and lunching at a variety of picnic tables. Since state park cabins are virtually identical, inside and out, I rarely knew on whose couch the children and I were snuggled.

Oh, and it rained, which created mud and general dampness, and by the time we departed, “grubby” was the word that described the well-used bag in the car next to the dog. (“Grubby” was the word for the dog, too.)

To be honest, the bag was on its way to grubby long before its weekend at the cabins. One afternoon, my older grandson and I went out for ice cream, taking the bag of books with us. The plan was to read while he had a treat, an agenda he and I both thought brilliant.

When he had his cone with sprinkles, I opened a book, only to realize the ice cream, even when I held a cup under it and frantically stanched drips with napkins, was melting like a Salvador Dalí picture. Eventually we abandoned the book altogether until the last sprinkle had been consumed and both boy and his immediate vicinity had been all but hosed down. Then we moved to a sunny bench and resumed reading while ice cream customers swarmed around us and small children edged up to listen, as small children always do. I was in the middle of a book when my grandson reached over, took my arm, and pulled it around himself. Never let anyone tell you reading doesn’t have its rewards.

Reading in the car used to be easy. I’d climb in the back next to whichever grandchild was along; nothing to it. Now our car’s back seat has two child seats, complicating reading on the road (and rendering driving when we go out with friends impossible). Still, the bag of books is on the floor behind me, and I’m getting better at reaching around, pulling out a book, holding it high enough for the listener in back to see the pictures but not so high as to block the rear-view mirror or whack the driver — a.k.a. Grandpa — in the head. To see the words, I angle my neck like a Picasso figure. Easy-peasy.

Other spots for spur-of-the-moment stories: Park gazebos. Coffee shops. Front steps. Porch swings. And rocking chairs not far from small beds. That too, of course, goes without saying.