Fotomoto makes it easy to visually manage your image inventory by adding all of the images on your website that are larger than the "Minimum Width or Height for Images" setting to the Images page in the Fotomoto Dashboard. There you can easily control which images you want to sell by moving them in to various Collections with different product and pricing options.
To make images not-for-sale, simply move them to the 'Not for Sale' Collection, or you can change how Fotomoto handles images on your site. For more info, please see How do I exclude a photo from my store?