This is divided into:
Stock: i.e. items which are purchased, not necessarily for a specific job or jobs, subdivided into Paper and Board, Ink, and Other stock.  Any or all of these can be defined as 'controlled stock'       for which the stock level is monitored so that new stock is ordered as it is needed.
and
Purchase orders: which can either be for the refreshing of stock levels of controlled stock, or for one-off purchases.
There is a brief overview here.
In this menu we also have a program to maintain records for suppliers.