We are always looking to meet and go beyond your quality expectations. In order to meet these standards we require high resolution images when creating your custom shin guard designs. All images must be 300 DPI. Below is an example of how the image quality warning is calculated.
A print area of 10 cm and value for output file at 300 DPI. It means the final print-ready output will be of 1181px:
10cm / 2.54 = 3.93 inches (to transform cm in inches)
3.93 in * 300 DPI = 1181 pixels
An image of 500 pixels is uploaded and enlarged to cover the entire print area, the image will be resized to 1181px and you'll loose quality because the original image size was 500px.