The Y Size box contains a value which specifies the height of a page of paper in master units. If the paper size is predefined, UniTool will provide this value; however, if the paper size is defined by the user, you must specify this value.
For the Diconix 150 Plus printer, the value that appears in the Y Size box is 6336. UniTool determined this value by multiplying the paper height (11 inches) by the vertical-master unit (576 dots per inch).
For the HP LaserJet IIP printer, the value that appears in the Y Size box is 3300. UniTool determined this value by multiplying the paper height (11 inches) by the vertical-master unit (300 dots per inch).