The perfect book. This is how designer-genius Jan Tschichold described this system. Not the ok book, nor the pretty good book, but the perfect book.
This method existed long before the computer, the printing press and even a defined measuring unit. No picas or points, no inches or millimeters. It can be used with nothing more than a straight edge, a piece of paper and a pencil.
And you can still use it. This is a system which is still as valid, beautiful and elegant with ultra-modern design as it ever was for the work of the scribes, Gutenberg and Tschichold.