Why image resolution is important? Well, no one likes to see their printed images pixilated or fussy. Image resolution indicates the quality of the image when printed. Image resolution is indicated as DPI. DPI stands for (Dots per Inch). Basically, it means the amount of printable dots in the square inch of the image. More dots per inch – is better. More dpi means more image information, which means that you can scale up image for printing.
The ideal image resolution for an offset and digital printing is 300 dpi. For a large format printing like 18” x 24” poster 200 dpi, as it will not be looked up close but on a distance. And for a grand format printing like a 4ft x 8ft vinyl banner the ideal image resolution is 150 dpi. And remember – more dpi is not less.
So how do we determine DPI? Image width and height are indicated in pixels. So, for example in Windows if you will navigate to the folder where your images are stored and select the image, at the bottom of the window explorer you will see the image dimensions in pixels. Let’s say your image dimensions are 1024px X 768px and you would like to print it on your business cards. Now, we know the ideal image resolution for offset and digital printing is 300 dpi. To get the maximum printable size of this image, we need to divide image dimensions to ideal image resolution.
Width: 1024 / 300 = 3.4” Height: 768 / 300=2.5”
So the maximum image size that you can print is 3.4” x 2.5”. If you want to increase image size then your image resolution will drop which will result in a bad image printed quality. When designing your print material please keep in mind the maximum image size.
Now, you might notice that on the monitor you can scale up that image without loss of the quality. How come? Most of the monitors support 72dpi, which means that they can display your image bigger without losing the quality. So, don’t be tricked and check you image resolution for printing when working on your design.