How to print your document
When the MFC receives data from your computer, it begins printing by picking up paper from the paper tray. The paper tray can feed many types of paper and envelopes.
1 From your computer select the Print command.
If your computer is also connected to any other printers, select Brother MFC-8420or MFC-8820D (USB) Printer as your printer driver from the Print or Print Settings menu in your software application, and then click on OK to begin printing.
2 Your computer sends a print command and data to the MFC.
3 The LED blinks in yellow and the MFC starts to print.
You can select the paper size, and orientation in your application software.
If your application software does not support your custom paper size, select the next largest paper size.
Then adjust the print area by changing the right and left margins in your application software.

11 - 2 USING THE MFC AS A PRINTER