Merging Aperture projects is something that I very rarely do. Aperture projects represent the way that images were acquired, and it is unusual for two separate projects to have the same circumstances and therefore belong together.

But here is an example of merging that does make sense: two people shoot the same event at the same time and later each imports their own images into a separate Aperture project to do some initial rating and tagging. Once that is complete, these images could all be merged into a single project (for the event). Now in the same project, stacks can be built from images of a single subject taken simultaneously but from different viewpoints. As separate projects stacks could not be built this way because Aperture requires that all images in a stack come from the same project.

Another advantage of combining projects is that since projects can be exported, this creates a single archivable collection of images, ratings, and metadata.

I will merge these two projects Home and Garden into a single project called Home and Garden:



I select Home, ensure that all the images are visible by clicking on the X in the filter, and select all the images with command A. Then I just drag and drop those images into the Garden project:



That moves the master files into the Garden project if they are managed. If they are referenced, then they stay where they are, but the references to them are moved. Finally I double click Garden to rename it to Home and Garden and delete the now empty Home project. There should be no warning when I delete the Home project: it is empty. If for some reason it is not empty, then this dialog will appear:


And I have to cancel and figure out why images are left in the project before proceeding.

Any albums, galleries, light tables, or smart albums that reference images in the merged projects are not affected by the merge, as would be expected.

There are alternatives to merging projects. Putting the projects into a common blue folder is almost as good as merging the projects. If the blue folder is selected thee bowser will show the contents of the projects intermingled. Blue folders can be nested and so allow a whole hierarchy of projects and project groups to be filtered and browsed. This allows the projects themselves to be small and fast, while the scope of browsing is wide. Filtering works as expected too. Here I have several projects in blue folders and also blue folders in blue folders:



But using a common blue folder has one significant disadvantage: stacking will not work if an attempt is made to include images from more than one project.

Creating an album that contains the sum of the images in a number projects achieves many of the same goals as having a single merged project. It also allows images to be manually discarded without resorting to rating, deleting, or filtering. This allows you to weed out every frame that contains the one guest that everyone would prefer to forget without adding complex keywording. An album of this sort can be located anywhere in the library, inside or outside of any project or blue folder.

Another way of grouping the images from many projects is through a smart album. If all of the images in the two projects share a common keyword or other metadata, then that can be used to find all the images in both projects and a smart album created to recreate the set at any time.

Keeping projects separate can be useful for exporting images or using referenced masters. The dialogs for these actions include the ability to define a folder organization and using the project name is one of the selectable elements:



So in the example used at the beginning, having a separate project for each shooter would allow the images for the whole event to be exported into two folders, one per shooter, together with a different folder structure above and below those folders.

Another potential problem with merging projects is that it can make archiving and moving them difficult simply because of their size.