To print from the database you have to create a logical printer in IFS. This enables you to talk back to the application server. Then you have to have a print agent installed on a server. In the config file of the print agent you define the path to the printer.
The print agent install is found in your IFS home. Besides being able to print from the database it can also help with sites that have slower network access, by installing the agent locally. You can effectively cut the network traffic size down to the size of the PDF instead of the binary print image sent to the printer.
I would direct you to the Technical Documentation in IFS and search for Logical Printers.
The only other options available through oracle gets into some involved problems dealing with access control lists and talking directly to print drivers. Not for the faint of heart.