An image data communication system provided herein allows a customer to upload and save a digital image data file in a first resolution format to a server of a photofinishing service over a network. The photofinisher establishes a range of print sizes of acceptable quality based on the first resolution of the image data file. When the customer places a print order, the system compares the requested print size to the resolution of the saved image data file. If the requested print size is within the acceptable print quality range, the order is processed and shipped or otherwise made available to the customer. If the requested print size is outside the acceptable quality print range, the customer is notified and given the option of uploading the same image in a second resolution which is higher than the first resolution, after which the photofinisher processes the order using the second resolution.