turtle back
n.— «I have seen books labeled field guides that are too big or heavy to be comfortably carried on a hike. The guideline is that the book be less than 5 inches wide, 8 inches high and about 1 inch thick so it will fit in a jacket or pants pocket. More importantly, the cover should be some sort of soft material, such as paper, viny, or what is called a turtle back, so the book is a little flexible.» —“Field guides make great gifts for outdoorsy types” by John Ross Tribune-Review (Pittsburgh, Pennsylvania) Nov. 26, 2006. (source: Double-Tongued Dictionary)
Further reading
Astronauts returning from space say they experience what’s called the overview effect, a new understanding of the fragility of our planet and our need to reflect on what humans all share as a species. A book about the end of the universe...
There was a time when William Shakespeare was just another little seven-year-old in school. Classes in his day were demanding — and all in Latin. A new book argues that this rigorous curriculum actually nurtured the creativity that later flourished...