NATURE UNDERGROUND. THE ENDLESS CAVERNS. In the Heart of the Historic Shena ndoah Valley

wrappers : Paperback or softbound. Also, wraps.

plates : Full page illustrations or photographs. Plates are printed separately from the text of the book, and bound in at production. I.e., they are not sewn as parts of gatherings.

4to : Or quarto. A term used generally to describe the approximate size of a book, a book that is about 10" to 12" tall and roughly squarish in shape. The term is based on the size of paper traditionally used by book printers which has been folded and cut into 16 pages.

tipped in : used to describe something which has been glued into a book, for example a bookplate.