If you would like to be able to burn a single disc, multiple times, OS X allows you to do this without having to buy rewritable CDs or DVDs. This allow you to maximize disc space usage as you can use the disc multiple times to burn smaller folders and files.
The disc you will create is called a multisession disk. Each time you burn additional data onto the disc, a new disc icon will appear separately on the desktop when the disc is inserted. Each icon will represent a burning session.
To create the multisession disc:
1. Gather the files and folders that you wish to burn into a new folder.
2. Go to Applications, Utilities and open Disk Utility.
3. Go to the Menu and click File, New and select Disk Image from Folder.
4. When prompted, browse to the folder that contains the data you wish to burn.
5. Click Image.
6. Input a name for the disk image that will be created.
7. Specify the location that you wish the image to be saved to.
8. Click Save.
9. When the image has been created, return to Disk Utility.
10. Click the Burn icon on the toolbar.
11. Navigate to and select the newly created image file.
12. Click Burn.
13. When the Burn Disc dialog box appears, click the blue arrow.
14. Check the Leave disc appendable checkbox.
15. Click Burn.
The image will be burned to disc. When you wish to burn additional data to the disc, repeat the above steps. When you get to the dialog box, the Burn button will be replaced by an Append button.