As symbols of love for libraries go, cutting up books wouldn't be most readers' first thought. But the delicate paper sculptures that have been left anonymously in recent months around Edinburgh's cultural institutions have been enchanting.

The latest, and it seems the last, of 10 such ornaments has been found in the Scottish Poetry Library, just off the capital's Royal Mile where the mystery began in March when staff there found the first gift from the Banksy of books … Booksy, perhaps.

A note left with the sculpture reads: "'You need to know when to end a story,' she thought. Often a good story ends where it begins. This would mean a return to the Poetry Library. The very place where she had left the first of the ten. So, here, she will end this story, in a special place … A Poetry Library ….. where they are well used to 'anon.' Cheers Edinburgh It's been fun!"

Despite global coverage on the internet, with sites like NPR, Boing Boing and this very books blog reporting on the fragile finds, it seems nobody knows who has been making the sculptures.

But as Lilias Fraser, reader development officer at the poetry library, explains in this Audioboo clip, the secrecy is part of the fun.

"These sculptures are just an extraordinary gesture. It's obviously someone who wasn't looking to be recognised or to make money or even a commission out of what she was doing. It is an extraordinary thing that someone has done these beautiful things for absolutely nothing other than pleasure and interest and enthusiasm and love for places and books."

The second in the series was discovered in June by staff at the National Library of Scotland; a delicately crafted gramophone made out of Ian Rankin's Exit Music. Later in the month the city's Filmhouse found a tiny cinema made of books. And in July staff at the Scottish Storytelling Centre found a paper dragon's egg hatching on a windowsill.

These were followed by two discoveries at August's Edinburgh International Book Festival, dedicated to the City of Literature Trust and the book festival itself.

I remember haring around the festival site hunting for clues, along with some of the festival staff, trying to work out who had managed to smuggle in such a delicate artwork. Perhaps we'd find someone with a big box, or a bag. But the hunt quickly died down when we agreed that the thrill was in the secret.

Later that month the city's Central Lending Library staff found a paper magnifying glass pointed towards an Edwin Morgan quote: "When I got in I want it bright, I want to catch whatever is there in full sight."

The National Museum of Scotland and Edinburgh's Writer's Museum were the final recipients of the mystery sculptures, all of which have been photographed by local literary fan Chris Scott.

The local newspaper recently speculated that a city art student was the sculptor. But for me, finding out would spoil the fun. In a strange way the anonymity feels like a collective voice speaking up for all who share a fondness for libraries, at a time when many need support.