Some users have documents which repeat every X pages and they want to treat each part as a separate document, e.g. printing the first page to one tray, then the next X-1 pages to another tray, then to go back to the first tray again. To do this, just select the length of each segment as shown in the image below. Tray Selector will then split the document up into segments of this size and print according to your settings. Please note splitting is only done for the main print settings, not the extra copies.