Have you ever sent images out for printing and realized when you got the prints back that part of the image had gotten cropped out? That’s because different size prints use different aspect ratios.
Today’s digital cameras use one of two different aspect ratios – 4:3 or 3:2. Depending on the size of prints you want to make, your images may need to be cropped to fit. Applying the crop yourself before getting the image printed will ensure that none of the important parts of the image are lost.
You can resize images for print using Lightroom, Photoshop, GIMP and most other image editing programs. I’ll be using Photoshop in this tutorial because it’s what I use in my own workflow. The instructions for Photoshop and Photoshop Elements are pretty much identical, so this will work with both programs.
You should never permanently alter your original files. Always work on a copy of the image, never the original. If you crop the original file, you can never get that data back. Most images will need to be converted to JPEG or TIFF before printing anyway, so this shouldn’t be a problem.
Image Size & Resolution
To view the size and resolution of the image you’re working on, navigate to Image > Image Size. The dialog box that opens will show the current resolution of the image. The drop down menu at the top has display choices for showing the resolution in pixels, inches, mm, cm, etc..
When you view an image on the screen or use it for print, the resolution doesn’t matter. When you print the image, the resolution becomes much more important.
In order to have a smooth attractive print, the dots need to be small enough that you can’t see them. For photos, the general rule is 240 ppi.
Cropping the Image
If you try to crop the image using the Image Size window that was just open, the image will get stretched and distorted. To crop the image properly, we need to remove part of the image.
To select the crop tool, use the keyboard shorcut “C” or select it from the toolbar. Notice how the options bar at the top of the screen changed to show the crop tool’s options.
The box we’re interested in is on the far left. If you open the drop down menu, there are several options that set parameters for the crop. We want the W x H x Resolution option selected.
The three empty text entry boxes on the right are for entering the Width, Height, and Resolution for the cropped image. After you enter these values, a crop grid will appear over your image.
To select which area of the image gets cropped out, adjust the grid by clicking and dragging. You can resize the grid by clicking on the corners. The ratio will stay fixed. Once you’re ready to apply the crop, hit “Enter”.
If you return to the image size dialog box again, you can see that the dimensions and resolution have been changed. The image is now ready to be printed.