Resolution equals the quality of the image. Resolution is expressed in dpi (dots per inch). The higher the number of “dots” per inch, the sharper and higher the quality of the image. In order to be able to deliver a good quality of printed matter, we need a file with a resolution of 300 dpi. If the resolution is too low, you will get a blurry or jagged (block effect) result.

How can I check or adjust the resolution?

Open the design or image in Photoshop. In the menu bar, click Image → Image Size. In the window that appears you can check the settings of the design or image. Make sure that the ‘Resolution’ box reads 300 pixels/inch. If not, you can adjust it to 300 pixels/inch. After adjusting the resolution, you also check the dimensions. These must be actual size (or possibly larger).