Use Stacking to keep your photo collection visually tidier. To work with photo stacks, use the commands available in the toolbar for the Information panel, or in the right-click menus for thumbnails in the Browser, or from the main menu: Organize | Stacking. Select multiple photos in the Manager and use Include in Stack. Stacked photos are listed as a single item, and a stack can be worked with as if it were a single photo. At the top right of each stack is a number indicating how many photos are in the stack. Click it to collapse or expand the stack. To visually represent the stack using a different photo than the first one in the list, select the desired photo and use Set as Main File in Stack. To remove individual photos from a stack, use the Exclude from Stack option. To unstack files, select at least one file in the stack and then use Unstack.

Use Create Variant to create a new version of a given photo within the ZPS X environment. This new version includes all the changes you’ve made to it in Develop. You can create any number of Variants for a photo.  Create Variant does not produce a copy of the file on your hard drive; Variants are stored in small auxiliary .data-zps files. Variants cannot be moved among folders, because each Variant is tied to the original copy of a photo file. Despite this, each Variant behaves like a separate file, and you can make standard edits and adjustments to them and export them. A photo’s original and all of its Variants are merged into a stack and behave as one. This stack can be unstacked, and you can then work with all the Variants separately. Materialize Variant creates a non-virtual copy of the original file and an auxiliary file containing your changes from Develop, and the Variant is removed. If the Variant was in a stack, that copy will stay in the stack. The option named Overwrite Source File With Variant is only available for Variants. Using it applies your changes from the Develop module to the original photo and deletes the Variant.