Comic Life uses the .comic file format to save and preserve your artwork, should you wish to edit it at a later date. If you want to save your artwork as a Jpeg, you'll need to export it within the application itself.
1. Start Comic Life and open your artwork.
2. Click File → Export → Export to Image(s)...
3. Click on the drop-down menu next to "Format" and select the image format you want to use; you've got a choice between TIFF, GIF, JPEG and PNG. Once you're happy with the settings, select a destination on your hard drive and click the "Export" button. Your artwork will now be saved in the chosen image format.
Note: When you click export, a folder will be created with the image file inside. For example, after following the steps above, I decide to name my artwork "Yahoo" and export it to my Desktop. There'll be folder on my Desktop called "Yahoo", and inside this folder will be the JPEG image.