Book conditions

As New
It means that the book is in the state that it should have been in when it left the publisher. The is the equivalent of Mint condition in numismatics.
Fine (F or FN)
Is As New but allowing for the normal effects of time on an unused book that has been protected. A fine book shows no damage.
Very Good (VG)
Describes a book that is worn but untorn. For many collectors this is the minimum acceptable condition for all but the rarest items. Any defects must be noted.
Good (G)
Is (as an old bookselling joke has it) not very good. It is used to describe the condition of an average used worn book that is complete. Any defects must be noted.
Shows wear and tear but all the text pages and illustrations or maps are present. It may lack endpapers, half-title, and even the title page. All defects must be noted.
Describes a book that has the complete text but is so damaged that it is only of interest to a buyer who seeks a reading copy. If the damage renders the text illegible then the book is not even poor.
Ex-library or Book Club
These copies must always be designated as such no matter what the condition of the book.
Binding Copy
Describes a book in which the pages or leaves are perfect, but the binding is very bad, loose, off or non-existent.

Book sizes

Book formats and corresponding sizes
Name Abbr. Leaves Pages Inches [h×w]
Folio 2º or Fo 2 4 15 × 12
Quarto 4º or 4to 4 8 12 × 91/2
Octavo 8º or 8vo 8 16 9 × 6
Duodecimo or Twelvemo 12º or 12mo 12 24 73/8 × 5
Decimo-sexto or Sixteenmo 16º or 16mo 16 32 63/4 × 4
Decimo-octavo or Eighteenmo 18º or 18mo 18 36 61/2 × 4
Vingesimo-quarto or Twenty-fourmo 24º or 24mo 24 48 37/8 × 213/16
Trigesimo-secundo or Thirty-twomo 32º or 32mo 32 64 51/2 × 31/2
Sexagesimo-quarto or Sixty-fourmo 64º or 64mo 64 128 3 × 2