But there is no reason an ebook has to be a plank. E-ink paper can be manufactured in inexpensive flexible sheets as thin and supple and cheap as paper. A hundred or so sheets can be bound into a sheaf, given a spine, and wrapped between two handsome covers. Now the ebook looks very much like a paper book of old, thick with pages, but it can change its content. One minute the page has a poem on it; the next it has a recipe.
