a book sling of a generally u - shaped sling cradle is provided with first and second side walls , and a bottom disposed between the side walls upon which one or more books received in the cradle of the book sling rest . advantageously , the book sling has open sides and an open top enabling quick visual determination of which particular book should be taken out during use , thereby making it quicker and easier to use than a backpack that completely encloses everything such that it cannot be viewed without first opening the backpack .