Most images we receive for printing on canvas have .jpg extension. In fact our ordering system will only accept this type of files. There is no size limit set up on our side - it depends a lot on the actual speed of your internet connection. As most people have ADSL broadband connection - the letter 'A' stands for asymmetric as we can download with much greater speeds than upload (actually the difference is about 8 times). We have received files in excess of 40Mb via our website. However if you would like to create canvas prints from larger files or use other files extensions it is also not a problem. For all professional users and also if original image has been created in a different than .jpg format I would suggest not to change it to .jpg. Why? Very simple reason - jpg is actually a lossy compression, even at high/highest quality it still performs compression resulting in some image data being lost irreversibly. So if you take your photos in raw format please do not use jpg extension when saving your files out from Adobe Photoshop. Preferrable option will be either .tiff where either no compression can be chosen or LZW lossless compression or .psd file where again all image data is 100% kept. This is especially important when images are going to be enlarged in order to produce bigger canvas prints. So if you prefer to send us your file in a different than .jpg format I would suggest to create .jpg version and use it in our canvas photo prints ordering system, and once you are happy with the cropping and size just put a comment in the last step saying that you'd like to upload image in a different than .jpg type. We will then provide you with the details how to connnect to our ftp server - this will accept any type and size files. As ever - please don't hesitate to contact us in case of any question.