Setting the Height or Width of the Printed Output
By default, when you open the Print dialog, the printed output is maximized. That is, it is drawn to the largest scale that will fit on the selected paper size while maintaining the same aspect ratio. Within the limits of the selected page size and, if specified, the X origin and Y origin, you can set the scale, the X (width), or the Y (height) of your printed output. The settings for the width and height (the Size fields) and Scale are interlocked to preserve the aspect ratio of the print area. Changing one setting results in corresponding changes to the others.