Hi Rog, it is really up to you… the URL of the file that you enter will be delivered to the customer upon purchase.
Digital images can be easily copied from the browser so this is what I do…
1) resize the images I display using the NextGen Gallery to a smaller size.
2) apply watermark to the image using the NextGen Gallery “Effect” option.
This prevents stealing of images from the preview you display on the NextGen Gallery.
I store the real high res watermark free images on a separate location and use them as my deliverable. Once the purchase is complete the encrypted download link for the original image (1920×1200 resolution and no watermark) is emailed to the buyer.
Read the following post for more details on this topic: