Commercial web-to-print applications can include both print on demand (POD) or pre-printed materials that are pulled from inventory. POD documents can have static content or include elements of variable data printing (VDP), a form of POD that is mainly used for personalization of marketing materials with product or customer data that is pulled from a database. VDP is geared toward mass customization, whereas web-to-print focuses only on changes made from order to order. VDP pre-dates web-to-print although at that time the design process was carried out via close collaboration with the printer for documents such as invoices.