Selecting sheets for printing
User has ability to select separate part of drawing for printing. This ability is useful if printing of any sheets failed. There is no need to reprint the whole drawing. Just use mouse for excluding those parts of drawing which don't have to be printed.
If on scene of the sheet are drawn gray lines, that given page will not be printed.
As a matter of convenience choice printed/unprinted sheet serves the buttons Select All 
(notes all sheets printed) and Hide All 
(notes all sheets not printed).
Press Print 
button to print the image.