First off, you must have an android app device that supports GooglePrint to print invoices. If you do, awesome! Follow the instructions below to print out your invoices:

• Swipe over to Home and tap the Invoices icon
• Select the invoice to be printed
• Press and hold the settings option and select Print.
• This will take you to the Google Print access login screen where you can enter your user credentials.
• If the printer is already configured, automatically the page will list the printer(s).
  
• All you have to do is to select the printer and to confirm the printing of the invoice.
  

Note : If you have a printer which could support Bluetooth, then you can print the invoice(s) through the Bluetooth option from your Android app. In this case, you have to download the invoice as a PDF first. Then you can send the downloaded PDF to the Bluetooth configured printer.

For more information on GooglePrint, please visit the http://www.google.co.in/cloudprint/learn/