Aperture: How to crop images for print orders

Here's how to do it:

1. If you want to maintain a version of the image at its current aspect ratio, create a duplicate version by highlighting the image and choosing Images > Duplicate Version.
2. Select the crop tool by pressing the C key.
3. From the Aspect Ratio pop-up menu in the Crop HUD, choose the aspect ratio that matches the size print you plan to order.
4. Drag the crop tool over the image to highlight the portion you wish to include. When you're satisfied with the selection, press Return.

Here are the suggested crop ratios for print orders:

If you plan to order different size prints of the same image, you may need to create additional duplicate versions of the image, so that you can use an appropriate crop ratio for each print size.