Virtual paper pages will ultimately be printed, and therefore require paper parameters that coincide with international standard physical paper sizes such as "A4," "letter," etc., if not custom sizes for trimming. Some desktop publishing programs allow custom sizes designated for large format printing used in posters, billboards and trade show displays. A virtual page for printing has a predesignated size of virtual printing material and can be viewed on a monitor in WYSIWYG format. Each page for printing has trim sizes (edge of paper) and a printable area if bleed printing is not possible as is the case with most desktop printers.