- Insert Snow Leopard DVD.
- Launch Disk Utility
- Select DVD in left column
- Click New Image
- Name New Image ‘Snow Leopard Backup’ or whatever you choose. Click Save.
- When finished, do not mount disk image.
- In Disk Utility, Select Burn
- Navigate to the Disk Image you created and select and click Burn
Note: You will need a Dual Layer DVD for this process.