When I drag a folder into Apple Aperture the name of the folder becomes the name of a project that those photos are put in. Specifically, the metadata item is "Project path".
This information is important to me because the folders — and thus the projects — had good, descriptive names.
Now I want to move all my photos to Adobe Lightroom, and I would like to embed that metadata in the photo so it's present in Lightroom; maybe as a keyword or any field really. How can I accomplish this?