This page allows to prepare the imposed document for printing. You may split front and back pages, reverse their order and so on.
Depending on the printer you may want to split the imposed document to fronts and backs (for manual duplex) or leave them interleaved (for duplex printers). This is the first decision you need to make before you save the document.
Each mode has its own parameters that allows to flip sheets, reverse sheets order and print backs before fronts or vice versa. You may even save fronts and backs to separate documents.
Quartz filter field allows to process the imposed document with a filter. This is useful for colorspace conversion and various transformations of the document.