By default their size should be 587x543 pixels sharp.
Please note that since canvas area could be changed to any other dimension, all of your products should be resized accordingly.
The products may also contain masks. This is in particular useful for irregularly shaped products like phone wraps, where you'd like design to be shown behind the wrap shape. Masks can also be SVG or PNG (best for transparency) and sizes same as the product. When LiveArt is loaded with product and mask image, the mask will be on the top of the product image.
Product thumbnails for categories should be 110x110 pixels.
After respective images are prepared, update Product JSON with links to images and set desired printable areas. If your LiveArt is connected to any of our integration packages, you can find respective panel in admin area, e.g. of Magento or WooCommerce. You may also find plenty of examples in your development package or admin area (in case of complete solution).