When uploading a digital photo, ensure that it has a minimum resolution of 300 DPI or dimensions of at least 1500 pixels by 1500 pixels; larger sizes are acceptable. You can typically identify the photo's size within the file's properties. The dimensions of the photo for printing should be at least equal to the designated print area, though larger sizes are permissible and will be resized as needed. Photos smaller than the print area are not recommended, as they may lead to a loss of clarity and image degradation.