Resolution, Explained

Minuteman Press loves getting technical. We’ve shared information on computer file formats, going into detail about the differences between bitmaps and vectors. Resolution is one of those things that you probably have a vague idea of, but a thorough understanding is critical to ensure your graphics and images look great on your website AND enlarged on a poster.

The Basics

Digital images are made up of a myriad of small, square dots called ‘pixels’. These pixels come in different colours and densities. Essentially, that’s what resolution is: how many pixels are in an image per unit area. Low resolution means that an image is created out of very few pixels. Nearly all images you look at on a screen are low resolution. You might have noticed that if you zoom in on an image on your phone or computer it begins to look blotchy. That’s because you can see the pixels that make up the image when you enlarge it.

When you print images, the resolution has to be much higher to ensure those pixels remain undetectable. A photograph might look great on your smartphone, but the minute you try to print it out for framing, it can start to appear fuzzy and pixelated.


An image’s resolution is defined in Dots Per Inch (DPI), or Pixels Per Inch (PPI). These measurements mean exactly what they sound like they would: the number of pixels per linear inch. Because computer imaging was pioneered in the US, it’s standard to use Imperial units when describing resolution. The higher the number, the higher the resolution and therefore, the better the quality of the image.

DPI is often used to refer to images intended for printing, while PPI more often refers to the resolution of an image on a computer screen. Just to give you a basic idea, most electronic screens are around 90 PPI, whereas a high quality printed image should be at least 300 DPI.

Figuring Out the Resolution

So, the custom graphic design your company uses on your website and business cards needs to be enlarged and printed onto a banner. You’ll need to check the resolution first to make sure it is high enough. You can find the resolution of an image in a couple of different ways, depending on the file type.

Different Image Resolutions
Different Image Resolutions
If you can open your image in a photo editor like Photoshop, the menu will give you an option of ‘image size’ or ‘image properties’. For images online, you should be able to right click and ‘inspect image’ to get the resolution. If the only information you can find relates to the size of the file—usually given in kilobytes or megabytes, keep in mind that the larger the file, the higher the resolution.

If you’re looking for digital printing in Melbourne, choose Spencer Minuteman Press. We can help you understand and work out any problems you might be having with image resolution.