Please check the following:
 

• Is the printer driver properly installed?
  
  Open the "Setup Utility / Print Center" and then check if the printer driver for your P-touch has been registered.
  
  <Using the screen of the QL-570 as an example>
  
  
  If proper printer driver is not listed, install the printer driver again. You may need to uninstall the old software before installing.
  
  Uninstalling the Printer Driver
  1. Turn off the Brother printer.
  
  
  2. For Mac OS X 10.4.11
     Double-click the drive where Mac OS X is installed, and click [Applications]- [Utility (Utilities)] - [Printer Setup Utility (Print Center)].
     The [Printer List] dialog box appears.
     
     For Mac OS X 10.5.x - 10.7
     Click Apple menu - [System Preferences], and click [Print & Fax].
  
  
  3. For Mac OS X 10.4.11
     Select your printer model such as "Brother QL-500/550/650TD/1050/1050N", and click (Delete)
     
     For Mac OS X 10.5.x - 10.7
     Select your printer model such as "Brother QL-500/550/650TD/1050/1050N", and click (Delete)
  
  
  4. Close the [Printer List]/[Print & Fax] dialog box.
     The printer driver has been uninstalled.

• Is the correct printer selected?
  
  Select the "Printer Setup" from the "File" menu.
  
  
  Check if your P-touch/QL machine is selected under "Application Matching Printer".
  


• Is your P-touch/QL printer directly connected to the Mac's USB Port?
  
  You should not use the USB ports on the Mac keyboard. When connecting your P-touch to the Mac via a USB hub, a proper connection may not be possible due to the type of hub being used.