It's something that most of us have to do, from time to time: get rid of old books.
People moving house, someone whose partner has died, those simply needing more space who find that their bookshelves just aren't big enough.
Sarah Cuddon examines the difficult decisions behind the seemingly mundane choices we make when deciding which books stay and which books go.
Amongst the people she talks to are Brian, who lives in Dorset.
One shelf at a time, he wades through, weighing up a Delia Smith against a book about Spike Milligan.
Does it stay on the shelf? Should it go in the box? Angel is contemplating a vast and varied collection of valuable volumes left after the death of her husband.
Whilst Trevor in South East London peruses each title, skimming, pausing to reflect on his attachment to Boswell, Hunter S Thompson and James Lee Burke.
They all stare at their shelves and start making painful decisions, based on their human relationship with individual books.
What will happen to them? Sarah visits Britain's largest second hand bookshop, Bookbarn International which is home to around 3 million rejected and dejected titles all hoping for a new owner.
Every book has to justify its shelf space and Sarah discovers the fate of thousands of unwanted ones.
Many are sold for scrap and pulped.
Some are reprieved and shipped overseas.
Death, decomposition or liberation?
Arriving early, pavement bookseller Mike assesses junked books at a car boot sale.
Why doesn't he pick up Mr Nice by Howard Marx? It's a very personal and selective set of criteria, making decisions about which books are worth something and which books aren't.
As the stories unfold, we learn that the reasons people hold on to them are as individual as the books.
Producer: Tamsin Hughes
A Testbed production for BBC Radio 4.
The personal stories and painful decisions we face when getting rid of our old books.