How to create a Multi-session CD/DVD
From GEAR Software Knowledgebase
You create a multi-session disc the same way as you would create a CD/DVD-ROM, but with one exception: "Close as Multi-session" must be enabled in the Recorder/ device Settings. For DVD media multi-session is only supported with DVD-R and DVD+R media not with rewritable media like DVD-RW and DVD+RW.
1. Create a CD/DVD-ROM project as described in the procedure earlier this chapter.
2. In the Output Device panel, click Settings. The CD Recorder Settings window appears.
3. Set the Recording Method field to Track-at-Once.
4. Enable the "Close as Multi-session" checkbox.
5. Enable fixation (if you want to be able to read the CD between adding/appending sessions.)
6. Click OK. The Explorer view reappears.
7. Click Test to start testing and writing. GEAR will ask you if you want to write to CD-R(W) after the test has been successfully completed.
8. Click Yes. Once the writing session has been completed, the Mult-session CD/ DVD-R(W) can be used in a CD player capable of reading Multi-session CDs. You can add new data by appending a new session to the disc.