You can continue to make changes to a topic after creating the initial overlay this includes structural changes such as adding or deleting frames. The Microsoft PowerPoint overlay file is also preserved for subsequent exports of the topic for future editing. However, the original recorded screenshots are preserved so that you can remove all overlays from a topic. When you import the slides back to the Topic Editor, the overlay objects are merged into the screenshot and become part of the screenshot. Microsoft PowerPoint addes these objects as overlays on top of the slide. You edit a topic in Microsoft PowerPoint by advancing through each slide, adding graphics such as text boxes, callouts, pictures, and drawing objects to call attention to or cover (mask) specific areas of the screenshot.
