When I complete my photo book, I like to save all the source photos I used to make the photo book. The easiest way I found to do this is to select the album in the Photos app sidebar and from the menu select File > Export. Unfortunately, this exports ALL the photos in the project, not just the ones actually used in the photo book. To only export the photos used in the photo book, I have to delete the unused photos from my project first. In my last project, I had 350+ unused photos. Clicking the Trash Can icon on each of those unused photos is quite tedious. To make matters worse, after trashing 10 or so unused photos, the trash can icon disappears from the remaining photos. The only way I have found to get the trash can icon to return, is by scrolling the list of unused photos to the bottom and then back again up to the top. After this, the trash can icons reappear and I can delete another ten or so, when I have to scroll again and repeat the process. To make this process easier and less burdensome, please add a button or something similar that can remove all unused photos from a photo book in a single click. Thank You for your consideration.