Predicting how an image will look when printed is an important part of evaluating a file. Below are the steps to determine your monitor's resolution and how to use that resolution to view a file at the final print size.
- Determine Your Monitor's Resolution
- Setting Your Screen Resolution in Photoshop
- Setting your Print Dimensions
Determine Your Monitor's Resolution
The biggest challenge with using Photoshop, or other editing programs, to view an image at a desired print size is that your editing program has no way of knowing the size and resolution of your monitor. The default screen resolution in Photoshop is set to 72 PPI (pixels per inch), which is not likely to match the resolution of today's monitors.
To determine your monitor's resolution in Pixels Per Inch, we must first find your screen's native Pixel Dimensions:
Pixel Dimensions in Windows
Right click on your Desktop and select Display Settings or open your Start Menu and type Display Settings
Scroll down and find the Display Resolution field. Make sure the screen is set to its "Recommended" value; this is your monitor's native resolution in pixels. Record this first number (3840 in the example below). This is the number of pixels wide your screen is.
Pixel Dimensions in Mac OS
Click the Apple Icon in the upper left of your screen, select About This Mac, then More Info.
This will display your screen resolution in pixels. In the example below, you can see that the screen resolution is 1440×900.
If you click Display Preferences on that screen, you can change the screen resolution. Make sure "Best For Display" is selected to ensure you are viewing your monitor's native resolution.
Measure Screen Width
Using a ruler, measure your screen horizontally in inches. Measure just the screen itself, not including the frame or bezel.
Calculate Your Screen's PPI
Now that you have the Pixel Dimensions of your screen and the Width of your screen in inches, simply divide the first number of the Pixel Dimensions by the Width of the screen in inches to determine the number of Pixels Per Inch. Make a note of this value.
Example: My monitor has a pixel dimension of 3840 x 2160 and a screen width of 23.75 inches. So, I will divide 3840 pixels by 23.75 inches to get a screen resolution of 161.6 PPI (I'll round up to 162 PPI for convenience).
Enter Monitor Resolution in Photoshop
Now that we have our monitor's PPI value, we can add this to Photoshop.
Find the Units & Rulers section of your Preferences. Depending on your version and whether you’re on a Windows or Mac it will either be under Edit > Preferences or Photoshop > Preferences. The keyboard shortcut for opening the Photoshop Preferences dialog box is Ctrl+K on Windows and Cmd+K on Mac.
Photoshop Preferences on PC
Photoshop Preferences on Mac
In the Screen Resolution field, enter the PPI you just calculated for your monitor (which in the above example was 162).
Click OK to save these changes. This setting should not have to be changed again unless you switch to a new monitor.
Setting Your Print Dimensions
Now that you have given Photoshop the resolution of your monitor, you can now preview your files at a very close approximation to the final print output.
To do this, your image’s dimensions must be set to the dimensions of the final print. In our File Preparation Guidelines article, we mentioned that it is not necessary to resize your image to the final print size, but if you are looking to preview your file, it is necessary to adjust these values.
When you have your image open in Photoshop, open the Image Size window. The keyboard shortcut for opening the Image Size dialog box in Photoshop is Ctrl + Alt + i (Windows) or Command + Option + i (Mac).
Input the dimensions of your desired final print into the Width/Height fields and the Resolution of the printing process (300 PPI is standard).
Make sure the "Resample" box is checked and Click OK.
Now we will use Photoshop’s View settings to view your file at "Print Size". You can do this by clicking the View dropdown menu at the top of your screen and selecting Print Size...
Or by right clicking on your image when either the Hand or Zoom Tools are selected...
You will now see the image displayed on your screen at the print size which you have entered. This will help you to determine if your image is of sufficient quality for a print of the selected size.
You can verify that these settings were done correctly by turning on the ruler in Photoshop (View > Rulers) and comparing an actual ruler to the ruler shown along the edges of the image.
When evaluating your image, look for any obvious pixelation, lack of sharpness, or banding.
Also consider the distance at which the print will be viewed. Some imperfections may be overlooked at a longer viewing distance.
Do not save these size/resolution changes. It is recommended that you do not resize your images for printing unless you have a very specific reason for doing so. Bay Photo uses very high-end software to resize your files for the final print output.
Resolution Optimization
If you feel that your file is not going to be of sufficient size or resolution for the print size you are looking for, Bay Photo offers a Digital Artwork service in our ROES software called Resolution Optimization. This service is a combination of noise reduction, pixelation and compression artifact reduction, traditional upscaling, artificial intelligence upscaling, and sharpening.
This service can be found in the “Choose Retouching Options” tab next to the “Product Options” tab in any of our catalogs.