This delightful book is no bigger than my hand. Its type size is perfectly legible — 9 point, well leaded. It fits a pocket, as all magical companions should be able to.
It might not be good body armour, however. Is the breastplate size of current fiction and the vehicle-armor size of current non-fiction a reflection of the paranoia of our times?
What do you think about the size of books? Is small effete? Is super-size just right to go with the house and the car? Or, non-pejoratively, just right because it's more comfortable for what you want a book to be and do?
Where do you read, and how? How do you store your books, if you do?
As to type size and leading, should books be printed as if they're for the vision impaired; and if so, what do you think about newspapers and legal documents?