‖For′mat″ (fō̍r′mȧ″ or fō̍r′mät″), n. [F. or G. Cf. Formation.] (Print.) The shape and size of a book; hence, its external form.
The older manuscripts had been written in a much larger format than that found convenient for university work. G. H. Putnam.
One might, indeed, protest that the format is a little too luxurious. Nature.