Early books have some iron content in them. Heavily foxed pages can be hardly readable. Foxing is usually more prevalent towards the end papers and title pages rather than to pages in the middle of a book. Not to be confused with browning. Frontispiece Illustration near the front of the book, often found facing the title page of the book.
Jackets are removable and tend to become misplaced over time.
International Book Collectors Association collecting tip . Visit your library annual sale and buy beat up first edition books with jackets for almost nothing. Go to the internet and buy a fine first edition copy of the same book without a jacket. Remainder Mark A mark designating that the book did not sell at the published price. Leftover books were remaindered to wholesaler for discount sales.