Knowing various photo sizes and aspect ratios will avoid unwanted cropping of photos when printing. The ratio of width to height of the image is known as the aspect ratio and mismatching the cropped image with the print could result in portions of the original picture being chopped off or blank borders. Visuals Clipping says that previewing the crop before you print will preserve key subject and detail at the edges. This is a great feature for group photos and candid shots where every detail is important.