To mark your place in a book, do you turn over the corner of the page, or do you grab the closest thing and use it as a bookmark? How about bending back the spine of one of those fat paperbacks? Do you write in the margins, underline, doodle? Or is even the idea of any of these too terrible to contemplate?

I’ll happily do all of them; I like my books to look as if they’ve been read. A book that shows the marks of the reader means it was loved, or perhaps unputdownable. For me, toast crumbs in between the pages means it was read at the breakfast table, a bus ticket bookmark says it was open on the way to work, and a coffee stain shows it was read on a park bench during a lunch break.

I’m talking about the books I own rather than library books, although I do admit to underlining a few passages and scribbling in the margins of borrowed books when I was a student (and paying more attention to the sections underlined by previous readers). But I never went as far as the English playwright Joe Orton and his boyfriend Kenneth Halliwell (later, his murderer), who defaced 72 library books in the 1960s. They stole them from their local library because they didn’t like the selection on offer and doctored the blurbs on the inside and the pictures on the covers: pasting cutouts of giant cats on an Agatha Christie novel and The Three Faces of Eve, among many other changes. The pair were caught after a sting operation and sentenced to six months in prison.

Perhaps such extensive defacing of library books happens less frequently now, but it seems we still like to leave things behind in the books we read. Tin House, the publisher of my novels, recently asked librarians to describe the most interesting, memorable, or just plain weird thing found in a book. Some answers weren’t so surprising—they were probably what the borrower had at hand to keep his or her place: a photograph, a ticket to a play, a wine label. More interesting were the three lots of money, the two paychecks, and the divorce papers.

However, what’s puzzling is the quantity of food the librarians found: a whole cooked shrimp (Was it flattened? Did it smell?), pickle slices, french fries, and a Pop-Tart. Three reported finding slices of bologna left between the pages. I do like to snack while I read, but generally the food doesn’t end up as a bookmark. Maybe it’s because I’m a writer, but I can’t help thinking about the readers here. Perhaps bologna is the snack of choice for children who have just come home from school: quick, cheap, and easy. Read your library book and I’ll give you a slice of bologna. Unfortunately the librarians didn’t say whether the slices of bologna were all found in children’s books.

But what about the two occurrences of raw bacon? Why raw? Somehow, I can understand cooked bacon. Perhaps breakfast has been put in front of the child—the one who didn’t eat the bologna the afternoon before (now that the child knows nothing bad will come from leaving food in library books)—and he or she doesn’t like bacon. Where better to hide it than in between the pages? But raw? I can’t even begin to think up a scenario for raw bacon.

One of the three winners of the Tin House competition found a taco “perfectly preserved and pressed like a flower in the middle of a book.” Another, amazingly, came across a photograph (printed in the book) of her Russian grandparents and uncle who had been persecuted for their religious beliefs. And the third found a sealed, stamped envelope that had never been sent. The librarian who discovered it said she put it in the post; I’m sure I couldn’t have resisted steaming it open first. There’s a story in the making around what the recipient thought when the letter arrived.

I will continue to turn over the corners of my books, drink coffee while reading them, and write in the margins, while I’ll carry on treating library books a little more gently. But perhaps now and again I’ll leave something in one before I return it: an old photograph, a cinema ticket, maybe even a little note to the next reader. What about you?

Claire Fuller’s second novel Swimming Lessons was published by Tin House in February.