A drawing assembled in bound form. It can be A-size or larger.
Even though the command media of some companies explicitly prohibits multiple volumes of a book-form drawing, some parts of said companies do it on a regular basis. These volumes are (confusingly) referred to as “sheets”…even though each page of each volume is termed “sheet” in the title block (go figure!). This whole notion can lead to considerable misinterpretation if references to the book are not clear from the context.
Contrast with sheet-form.