The bigger, the better. What matters is the actual size of the image in pixels (e.g. 3600 x 4800 pixels).
When you take a picture of an artwork, you can adjust the quality of the photo, including pixel resolution, in the camera settings.
You may want to process the image in a graphic editor (e.g. Adobe Photoshop) before uploading the image to Jose Art Gallery, but in any case DO NOT FORCE INCREASE THE PIXEL SIZE OF THE IMAGE. Such artificial enlargement may result in that the image is blurry, blocky, and unprintable.
Since our staff checks every image that will be available for printing, images of poor quality and artificially enlarged will be rejected from the “Print” option.
If you want a larger version of the image, you need to take a higher resolution camera. This is the only way to increase the size of your images.