The 162-strong combined populations of North Ronaldsay and Papa Westray look forward to the surprises thrown up by their twice-weekly book deliveries from the main library in Kirkwall.
They have been arriving since 1954, initially in North Ronaldsay, before the Family Box Service was rolled out to the other outer islands. It was introduced because the mobile library vans have difficulty negotiating the ferry slipways to reach them.
Residents are delighted by surprise titles libraries put in the dozen or so books which arrive by ferry or plane, after they have filled in a list of their preferences.
Crime writer Ann Cleeves, whose Shetland-based Jimmy Perez novels are a firm favourite, has visited to celebrate the anniversary.
She said: "It was fantastic to talk to islanders about the box scheme and to share stories with the children and the adults. Tea, home bakes and chat about books: what a great way to spend a winter's morning."
Former Herald journalist Jim Hewitson, who moved to Papa Westray more than 25 years ago, is about to publish his first novel, the referendum-inspired "Down in the Glen Something Stirs.'
He said: "The library staff in Kirkwall are so good at recognising your core interests, but every so often they will include something you are not anticipating.
"In these days of internet and Kindle, there is something so agreeable about opening up the box to see what you are going to be reading for the next few weeks, especially here in Orkney where there is still a real tradition of reading ."
Maureen Johnstone, her partner David and two children moved to North Ronaldsay three-and-a-half years ago.
She said: "We don't get into town very often, and when we do we've got so much to get done that it's hard to slot in some time to wander about the library. So when the box comes through every month it's a little bit like Christmas."