Limited Number of Items when Printing

We need to print 'Manuals' for clients. For example, we may be asked to supply our 'Safety Manual'. Having moved to Promapp, the way to supply this is to print the 'Safety Process group' with all associated processes. However we keep getting an error saying there are too many items to print.
Please look to increase the items limit (if a limit is required at all).
Its also not clear what an 'item' is.